diff --git a/CHANGELOG.md b/CHANGELOG.md
index 782a32c4e5..7b26ea322b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,6 +31,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - [#4654](https://github.com/apache/trafficcontrol/pull/4654) *Traffic Ops, Traffic Portal* Switched Delivery Service active state to a three-value system, adding a state that will be used to prevent cache servers from deploying DS configuration.
 
 ### Fixed
+- [#6229](https://github.com/apache/trafficcontrol/issues/6229) *Traffic Ops* Fixed error message for assignment of non-existent parameters to a profile.
 - [#7231](https://github.com/apache/trafficcontrol/pull/7231) *Traffic Ops, Traffic Portal* Fixed `sharedUserNames` display while retrieving CDN locks.
 - [#7216](https://github.com/apache/trafficcontrol/pull/7216) *Traffic Portal* Fixed sort for Server's Capabilities Table
 - [#4428](https://github.com/apache/trafficcontrol/issues/4428) *Traffic Ops* Fixed Internal Server Error with POST to `profileparameters` when POST body is empty
diff --git a/lib/go-tc/parameters.go b/lib/go-tc/parameters.go
index 95baca4fbd..57cce3206f 100644
--- a/lib/go-tc/parameters.go
+++ b/lib/go-tc/parameters.go
@@ -1,19 +1,5 @@
 package tc
 
-import (
-	"bytes"
-	"database/sql"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"strconv"
-	"strings"
-
-	"github.com/apache/trafficcontrol/lib/go-util"
-
-	"github.com/lib/pq"
-)
-
 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
@@ -33,6 +19,20 @@ import (
  * under the License.
  */
 
+import (
+	"bytes"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/apache/trafficcontrol/lib/go-util"
+
+	"github.com/lib/pq"
+)
+
 // ParametersResponse is the type of the response from Traffic Ops to GET
 // requests made to the /parameters and /profiles/name/{{Name}}/parameters
 // endpoints of its API.
@@ -210,10 +210,10 @@ func (pp *PostProfileParam) Validate(tx *sql.Tx) error {
 	}
 	if pp.ParamIDs == nil {
 		errs = append(errs, errors.New("paramIds missing"))
-	} else if ok, err := ParamsExist(*pp.ParamIDs, tx); err != nil {
-		errs = append(errs, errors.New(fmt.Sprintf("checking parameter IDs %v existence: "+err.Error(), *pp.ParamIDs)))
-	} else if !ok {
-		errs = append(errs, errors.New(fmt.Sprintf("parameters with IDs %v don't all exist", *pp.ParamIDs)))
+	} else if nonExistingIDs, err := ParamsExist(*pp.ParamIDs, tx); err != nil {
+		errs = append(errs, fmt.Errorf("checking parameter IDs %v existence: %w", *pp.ParamIDs, err))
+	} else if len(nonExistingIDs) >= 1 {
+		errs = append(errs, fmt.Errorf("parameters with IDs %v don't exist", nonExistingIDs))
 	}
 	if len(errs) > 0 {
 		return util.JoinErrs(errs)
@@ -277,12 +277,15 @@ func ParamExists(id int64, tx *sql.Tx) (bool, error) {
 
 // ParamsExist returns whether parameters exist for all the given ids, and any error.
 // TODO move to helper package.
-func ParamsExist(ids []int64, tx *sql.Tx) (bool, error) {
-	count := 0
-	if err := tx.QueryRow(`SELECT count(*) from parameter where id = ANY($1)`, pq.Array(ids)).Scan(&count); err != nil {
-		return false, errors.New("querying parameters existence from id: " + err.Error())
+func ParamsExist(ids []int64, tx *sql.Tx) ([]int64, error) {
+	var nonExistingIDs []int64
+	if err := tx.QueryRow(`SELECT ARRAY_AGG(id) FROM UNNEST($1::INT[]) AS id WHERE id NOT IN (SELECT id FROM parameter)`, pq.Array(ids)).Scan(pq.Array(&nonExistingIDs)); err != nil {
+		return nil, fmt.Errorf("querying parameters existence from id: %w", err)
+	}
+	if len(nonExistingIDs) >= 1 {
+		return nonExistingIDs, nil
 	}
-	return count == len(ids), nil
+	return nil, nil
 }
 
 // ProfileParametersNullable is an object of the form returned by the Traffic Ops /profileparameters endpoint.