diff --git a/src/QirRuntime/lib/QIR/callables.cpp b/src/QirRuntime/lib/QIR/callables.cpp
index 503ae8c1bf6..f63bc44dc03 100644
--- a/src/QirRuntime/lib/QIR/callables.cpp
+++ b/src/QirRuntime/lib/QIR/callables.cpp
@@ -181,13 +181,13 @@ int QirTupleHeader::Release()
     }
 
     assert(this->refCount > 0); // doesn't guarantee we catch double releases but better than nothing
-    --this->refCount;
+    int retVal = --this->refCount;
     if (this->refCount == 0)
     {
         char* buffer = reinterpret_cast<char*>(this);
         delete[] buffer;
     }
-    return this->refCount;
+    return retVal;
 }
 
 QirTupleHeader* QirTupleHeader::Create(int size)
diff --git a/src/QirRuntime/lib/QSharpFoundation/intrinsicsMath.cpp b/src/QirRuntime/lib/QSharpFoundation/intrinsicsMath.cpp
index cc22595ebe3..4a0a206d58a 100644
--- a/src/QirRuntime/lib/QSharpFoundation/intrinsicsMath.cpp
+++ b/src/QirRuntime/lib/QSharpFoundation/intrinsicsMath.cpp
@@ -12,7 +12,8 @@
 namespace // Visible in this translation unit only.
 {
 extern thread_local bool randomizeSeed;
-extern int64_t lastGeneratedRndNum;
+extern int64_t lastGeneratedRndI64;
+extern double lastGeneratedRndDouble;
 }
 
 // Implementation:
@@ -74,7 +75,7 @@ int64_t quantum__qis__drawrandomint__body(int64_t minimum, int64_t maximum)
 {
     if(minimum > maximum)
     {
-        quantum__rt__fail(quantum__rt__string_create(Quantum::Qis::Internal::excStrDrawRandomInt));
+        quantum__rt__fail(quantum__rt__string_create(Quantum::Qis::Internal::excStrDrawRandomVal));
     }
 
     // https://en.cppreference.com/w/cpp/numeric/random/uniform_int_distribution
@@ -83,8 +84,30 @@ int64_t quantum__qis__drawrandomint__body(int64_t minimum, int64_t maximum)
                                                 ? std::random_device()() :  // Default
                                                 0);                         // For test purposes only.
 
-    lastGeneratedRndNum = std::uniform_int_distribution<int64_t>(minimum, maximum)(gen);
-    return lastGeneratedRndNum;
+    lastGeneratedRndI64 = std::uniform_int_distribution<int64_t>(minimum, maximum)(gen);
+    return lastGeneratedRndI64;
+}
+
+double quantum__qis__drawrandomdouble__body(double minimum, double maximum)
+{
+    if(minimum > maximum)
+    {
+        quantum__rt__fail(quantum__rt__string_create(Quantum::Qis::Internal::excStrDrawRandomVal));
+    }
+
+    // For testing purposes we need separate generators for Int and Double:
+    // https://en.cppreference.com/w/cpp/numeric/random/uniform_int_distribution
+    // https://en.cppreference.com/w/cpp/numeric/random
+    thread_local static std::mt19937_64 gen(randomizeSeed
+                                                ? std::random_device()() :  // Default
+                                                0);                         // For test purposes only.
+
+    // https://en.cppreference.com/w/cpp/numeric/random/uniform_real_distribution
+    lastGeneratedRndDouble = std::uniform_real_distribution<double>(
+            minimum, 
+            std::nextafter(maximum, std::numeric_limits<double>::max())) // "Notes" section.
+        (gen);    
+    return lastGeneratedRndDouble;
 }
 
 } // extern "C"
@@ -92,7 +115,8 @@ int64_t quantum__qis__drawrandomint__body(int64_t minimum, int64_t maximum)
 namespace // Visible in this translation unit only.
 {
 thread_local bool randomizeSeed = true;
-int64_t lastGeneratedRndNum = 0;
+int64_t lastGeneratedRndI64 = 0;
+double lastGeneratedRndDouble = 0.0;
 }
 
 // For test purposes only:
@@ -102,17 +126,23 @@ namespace Qis
 {
     namespace Internal
     {
-        char const excStrDrawRandomInt[] = "Invalid Argument: minimum > maximum for DrawRandomInt()";
+        char const excStrDrawRandomVal[] = "Invalid Argument: minimum > maximum";
 
         void RandomizeSeed(bool randomize)
         {
             randomizeSeed = randomize;
         }
 
-        int64_t GetLastGeneratedRandomNumber()
+        int64_t GetLastGeneratedRandomI64()
         {
-            return lastGeneratedRndNum;
+            return lastGeneratedRndI64;
         }
+
+        double GetLastGeneratedRandomDouble()
+        {
+            return lastGeneratedRndDouble;
+        }
+
     } // namespace Internal
 } // namespace Qis
 } // namespace Quantum
diff --git a/src/QirRuntime/lib/QSharpFoundation/qsharp-foundation-qis.ll b/src/QirRuntime/lib/QSharpFoundation/qsharp-foundation-qis.ll
index 71b45b7c692..ac63ad53302 100644
--- a/src/QirRuntime/lib/QSharpFoundation/qsharp-foundation-qis.ll
+++ b/src/QirRuntime/lib/QSharpFoundation/qsharp-foundation-qis.ll
@@ -31,7 +31,7 @@
 %struct.QirString = type opaque
 %PauliId = type i32
 
-declare dllimport void @quantum__rt__message(%"struct.QirString"* %str)
+declare void @quantum__rt__message(%"struct.QirString"* %str)
 
 ;===============================================================================
 ;
@@ -64,6 +64,7 @@ declare double      @quantum__qis__arccos__body(double %theta)
 declare double      @quantum__qis__arctan__body(double %theta)
 declare double      @quantum__qis__ieeeremainder__body(double %y, double %x)
 declare i64         @quantum__qis__drawrandomint__body(i64 %min, i64 %max)
+declare double      @quantum__qis__drawrandomdouble__body(double %min, double %max)
 
 ; API for the user code:
 define dllexport double @__quantum__qis__nan__body() {                ; Q#: function NAN() : Double       http://www.cplusplus.com/reference/cmath/nan-function/
@@ -191,6 +192,15 @@ define dllexport i64 @__quantum__qis__drawrandomint__body(i64 %min, i64 %max) {
   ret i64 %result
 }
 
+; operation DrawRandomDouble (min : Double, max : Double) : Double
+; https://docs.microsoft.com/qsharp/api/qsharp/microsoft.quantum.random.drawrandomdouble
+define double @__quantum__qis__drawrandomdouble__body(double %min, double %max) {
+  %result = call double @quantum__qis__drawrandomdouble__body(double %min, double %max)
+  ret double %result
+}
+
+
+
 ;===============================================================================
 ; quantum.qis conditional functions
 ;
diff --git a/src/QirRuntime/lib/QSharpFoundation/qsharp__foundation__qis.hpp b/src/QirRuntime/lib/QSharpFoundation/qsharp__foundation__qis.hpp
index 5e64f5f0751..aa234b36170 100644
--- a/src/QirRuntime/lib/QSharpFoundation/qsharp__foundation__qis.hpp
+++ b/src/QirRuntime/lib/QSharpFoundation/qsharp__foundation__qis.hpp
@@ -40,6 +40,7 @@ extern "C"
 
     QIR_SHARED_API double quantum__qis__ieeeremainder__body(double x, double y);                // NOLINT
     QIR_SHARED_API int64_t quantum__qis__drawrandomint__body(int64_t minimum, int64_t maximum); // NOLINT
+    QIR_SHARED_API double quantum__qis__drawrandomdouble__body(double minimum, double maximum); // NOLINT
 
     // Q# ApplyIf:
     QIR_SHARED_API void quantum__qis__applyifelseintrinsic__body(RESULT*, QirCallable*, QirCallable*); // NOLINT
diff --git a/src/QirRuntime/lib/QSharpFoundation/qsharp__foundation_internal.hpp b/src/QirRuntime/lib/QSharpFoundation/qsharp__foundation_internal.hpp
index 6e923191efe..92ecfeb23f3 100644
--- a/src/QirRuntime/lib/QSharpFoundation/qsharp__foundation_internal.hpp
+++ b/src/QirRuntime/lib/QSharpFoundation/qsharp__foundation_internal.hpp
@@ -13,10 +13,11 @@ namespace Qis
 {
     namespace Internal
     {
-        extern char const excStrDrawRandomInt[];
+        extern char const excStrDrawRandomVal[];
 
         void RandomizeSeed(bool randomize);
-        int64_t GetLastGeneratedRandomNumber();
+        int64_t GetLastGeneratedRandomI64();
+        double GetLastGeneratedRandomDouble();
     } // namespace Internal
 } // namespace Qis
 } // namespace Quantum
diff --git a/src/QirRuntime/public/QirTypes.hpp b/src/QirRuntime/public/QirTypes.hpp
index 02b1d686f68..4809def635b 100644
--- a/src/QirRuntime/public/QirTypes.hpp
+++ b/src/QirRuntime/public/QirTypes.hpp
@@ -61,7 +61,7 @@ struct QIR_SHARED_API QirString
 using PTuple = char*;
 struct QIR_SHARED_API QirTupleHeader
 {
-    int32_t refCount = 0;
+    int     refCount = 0;
     int32_t aliasCount = 0; // used to enable copy elision, see the QIR specifications for details
     int32_t tupleSize = 0; // when creating the tuple, must be set to the size of the tuple's data buffer (in bytes)
 
diff --git a/src/QirRuntime/test/QIR-static/qir-test-math.cpp b/src/QirRuntime/test/QIR-static/qir-test-math.cpp
index b46b2ed4a1e..b544ce5c6a1 100644
--- a/src/QirRuntime/test/QIR-static/qir-test-math.cpp
+++ b/src/QirRuntime/test/QIR-static/qir-test-math.cpp
@@ -22,6 +22,7 @@ extern "C" uint64_t Microsoft__Quantum__Testing__QIR__Math__CoshTest__body();
 extern "C" uint64_t Microsoft__Quantum__Testing__QIR__Math__TanhTest__body();                                  // NOLINT
 extern "C" uint64_t Microsoft__Quantum__Testing__QIR__Math__IeeeRemainderTest__body();                         // NOLINT
 extern "C" uint64_t Microsoft__Quantum__Testing__QIR__Math__TestDrawRandomInt__body(int64_t min, int64_t max); // NOLINT
+extern "C" double Microsoft__Quantum__Testing__QIR__Math__TestDrawRandomDouble__body(double min, double max);  // NOLINT
 
 TEST_CASE("QIR: Math.Sqrt", "[qir.math][qir.Math.Sqrt]")
 {
@@ -97,7 +98,7 @@ TEST_CASE("QIR: Math.DrawRandomInt", "[qir.math][qir.Math.DrawRandomInt]")
         const uint64_t qsRndNum = 
             Microsoft__Quantum__Testing__QIR__Math__TestDrawRandomInt__body(std::numeric_limits<int64_t>::min(),
                                                                             std::numeric_limits<int64_t>::max());
-        const uint64_t cppRndNum = Quantum::Qis::Internal::GetLastGeneratedRandomNumber();  // This call must be done 
+        const uint64_t cppRndNum = Quantum::Qis::Internal::GetLastGeneratedRandomI64();  // This call must be done 
             // _after_ the  Microsoft__Quantum__Testing__QIR__Math__TestDrawRandomInt__body().
         REQUIRE(qsRndNum == cppRndNum);
     }
@@ -112,7 +113,7 @@ TEST_CASE("QIR: Math.DrawRandomInt", "[qir.math][qir.Math.DrawRandomInt]")
     }
     catch (std::runtime_error const& exc)
     {
-        REQUIRE(0 == strcmp(exc.what(), Quantum::Qis::Internal::excStrDrawRandomInt));
+        REQUIRE(0 == strcmp(exc.what(), Quantum::Qis::Internal::excStrDrawRandomVal));
     }
 
     // There is a strong difference in the opinions about how the random number generator must be tested.
@@ -201,3 +202,31 @@ TEST_CASE("QIR: Math.DrawRandomInt", "[qir.math][qir.Math.DrawRandomInt]")
     //     }
 
 } // TEST_CASE("QIR: Math.DrawRandomInt", "[qir.math][qir.Math.DrawRandomInt]")
+
+TEST_CASE("QIR: Math.DrawRandomDouble", "[qir.math][qir.Math.DrawRandomDouble]")
+{
+    // Test that the Q# random number generator is a wrapper around the C++ generator:
+    size_t times = 1000;
+    while(--times)
+    {
+        const double qsRndNum = 
+            Microsoft__Quantum__Testing__QIR__Math__TestDrawRandomDouble__body(std::numeric_limits<double>::min(),
+                                                                               std::numeric_limits<double>::max());
+        const double cppRndNum = Quantum::Qis::Internal::GetLastGeneratedRandomDouble();  // This call must be done 
+            // _after_ the  Microsoft__Quantum__Testing__QIR__Math__TestDrawRandomDouble__body().
+        REQUIRE(qsRndNum == cppRndNum);
+    }
+
+    // Make sure the correct exception is thrown if min > max:
+    REQUIRE_THROWS_AS(Microsoft__Quantum__Testing__QIR__Math__TestDrawRandomDouble__body(10.0, 5.0), std::runtime_error);
+
+    // Check the exception string:
+    try
+    {
+        (void)Microsoft__Quantum__Testing__QIR__Math__TestDrawRandomDouble__body(10.0, 5.0);
+    }
+    catch (std::runtime_error const& exc)
+    {
+        REQUIRE(0 == strcmp(exc.what(), Quantum::Qis::Internal::excStrDrawRandomVal));
+    }
+} // TEST_CASE("QIR: Math.DrawRandomDouble", "[qir.math][qir.Math.DrawRandomDouble]")
diff --git a/src/QirRuntime/test/QIR-static/qsharp/qir-test-arrays.qs b/src/QirRuntime/test/QIR-static/qsharp/qir-test-arrays.qs
index efe2e706db7..67b966a3cd9 100644
--- a/src/QirRuntime/test/QIR-static/qsharp/qir-test-arrays.qs
+++ b/src/QirRuntime/test/QIR-static/qsharp/qir-test-arrays.qs
@@ -57,6 +57,7 @@ namespace Microsoft.Quantum.Testing.QIR {
             let res19 = ParityTest();
             let res20 = PauliArrayAsIntTest();
             let res21 = PauliArrayAsIntFailTest();
+            let res22 = TestDrawRandomDouble(0.0, 1.0);
             MessageTest("Test");
 
             // Conditionals:
diff --git a/src/QirRuntime/test/QIR-static/qsharp/qir-test-math.qs b/src/QirRuntime/test/QIR-static/qsharp/qir-test-math.qs
index 137718d76cd..1556fe939ba 100644
--- a/src/QirRuntime/test/QIR-static/qsharp/qir-test-math.qs
+++ b/src/QirRuntime/test/QIR-static/qsharp/qir-test-math.qs
@@ -66,6 +66,10 @@ namespace Microsoft.Quantum.Testing.QIR.Math {
         return DrawRandomInt(min, max);
     }
 
+    operation TestDrawRandomDouble(min : Double, max : Double) : Double {
+        return DrawRandomDouble(min, max);
+    }
+
     function Close(expected : Double, actual : Double) : Bool {
         let neighbourhood = 0.0000001;  // On x86-64 + Win the error is in 16th digit after the decimal point. 
                                         // E.g. enstead of 0.0 there can be 0.00000000000000012.