diff --git a/packages/bundler-plugin-core/src/build-plugin-manager.ts b/packages/bundler-plugin-core/src/build-plugin-manager.ts
index a014a934..6922153f 100644
--- a/packages/bundler-plugin-core/src/build-plugin-manager.ts
+++ b/packages/bundler-plugin-core/src/build-plugin-manager.ts
@@ -29,6 +29,16 @@ import {
 import { glob } from "glob";
 import { defaultRewriteSourcesHook, prepareBundleForDebugIdUpload } from "./debug-id-upload";
 
+// Module-level guard to prevent duplicate deploy records when multiple bundler plugin
+// instances run in the same process (e.g. Next.js creates separate webpack compilers
+// for client, server, and edge). Keyed by release name.
+const _deployedReleases = new Set<string>();
+
+/** @internal Exported for testing only. */
+export function _resetDeployedReleasesForTesting(): void {
+  _deployedReleases.clear();
+}
+
 export type SentryBuildPluginManager = {
   /**
    * A logger instance that takes the options passed to the build plugin manager into account. (for silencing and log level etc.)
@@ -534,8 +544,9 @@ export function createSentryBuildPluginManager(
           await cliInstance.releases.finalize(options.release.name);
         }
 
-        if (options.release.deploy) {
+        if (options.release.deploy && !_deployedReleases.has(options.release.name)) {
           await cliInstance.releases.newDeploy(options.release.name, options.release.deploy);
+          _deployedReleases.add(options.release.name);
         }
       } catch (e) {
         sentryScope.captureException('Error in "releaseManagementPlugin" writeBundle hook');
diff --git a/packages/bundler-plugin-core/test/build-plugin-manager.test.ts b/packages/bundler-plugin-core/test/build-plugin-manager.test.ts
index 9f3968eb..6c320b6c 100644
--- a/packages/bundler-plugin-core/test/build-plugin-manager.test.ts
+++ b/packages/bundler-plugin-core/test/build-plugin-manager.test.ts
@@ -1,10 +1,14 @@
-import { createSentryBuildPluginManager } from "../src/build-plugin-manager";
+import {
+  createSentryBuildPluginManager,
+  _resetDeployedReleasesForTesting,
+} from "../src/build-plugin-manager";
 import fs from "fs";
 import { glob } from "glob";
 import { prepareBundleForDebugIdUpload } from "../src/debug-id-upload";
 
 const mockCliExecute = jest.fn();
 const mockCliUploadSourceMaps = jest.fn();
+const mockCliNewDeploy = jest.fn();
 
 jest.mock("@sentry/cli", () => {
   return jest.fn().mockImplementation(() => ({
@@ -14,7 +18,7 @@ jest.mock("@sentry/cli", () => {
       new: jest.fn(),
       finalize: jest.fn(),
       setCommits: jest.fn(),
-      newDeploy: jest.fn(),
+      newDeploy: mockCliNewDeploy,
     },
   }));
 });
@@ -633,4 +637,136 @@ describe("createSentryBuildPluginManager", () => {
       });
     });
   });
+
+  describe("createRelease deploy deduplication", () => {
+    beforeEach(() => {
+      jest.clearAllMocks();
+      _resetDeployedReleasesForTesting();
+    });
+
+    it("should create a deploy record on the first call", async () => {
+      const manager = createSentryBuildPluginManager(
+        {
+          authToken: "test-token",
+          org: "test-org",
+          project: "test-project",
+          release: {
+            name: "test-release",
+            deploy: { env: "production" },
+          },
+        },
+        { buildTool: "webpack", loggerPrefix: "[sentry-webpack-plugin]" }
+      );
+
+      await manager.createRelease();
+
+      expect(mockCliNewDeploy).toHaveBeenCalledTimes(1);
+      expect(mockCliNewDeploy).toHaveBeenCalledWith("test-release", { env: "production" });
+    });
+
+    it("should not create duplicate deploy records when createRelease is called multiple times on the same instance", async () => {
+      const manager = createSentryBuildPluginManager(
+        {
+          authToken: "test-token",
+          org: "test-org",
+          project: "test-project",
+          release: {
+            name: "test-release",
+            deploy: { env: "production" },
+          },
+        },
+        { buildTool: "webpack", loggerPrefix: "[sentry-webpack-plugin]" }
+      );
+
+      await manager.createRelease();
+      await manager.createRelease();
+      await manager.createRelease();
+
+      expect(mockCliNewDeploy).toHaveBeenCalledTimes(1);
+    });
+
+    it("should not create duplicate deploy records across separate plugin instances with the same release name", async () => {
+      const managerA = createSentryBuildPluginManager(
+        {
+          authToken: "test-token",
+          org: "test-org",
+          project: "test-project",
+          release: {
+            name: "test-release",
+            deploy: { env: "production" },
+          },
+        },
+        { buildTool: "webpack", loggerPrefix: "[sentry-webpack-plugin]" }
+      );
+
+      const managerB = createSentryBuildPluginManager(
+        {
+          authToken: "test-token",
+          org: "test-org",
+          project: "test-project",
+          release: {
+            name: "test-release",
+            deploy: { env: "production" },
+          },
+        },
+        { buildTool: "webpack", loggerPrefix: "[sentry-webpack-plugin]" }
+      );
+
+      await managerA.createRelease();
+      await managerB.createRelease();
+
+      expect(mockCliNewDeploy).toHaveBeenCalledTimes(1);
+    });
+
+    it("should allow deploys for different release names", async () => {
+      const managerA = createSentryBuildPluginManager(
+        {
+          authToken: "test-token",
+          org: "test-org",
+          project: "test-project",
+          release: {
+            name: "release-1",
+            deploy: { env: "production" },
+          },
+        },
+        { buildTool: "webpack", loggerPrefix: "[sentry-webpack-plugin]" }
+      );
+
+      const managerB = createSentryBuildPluginManager(
+        {
+          authToken: "test-token",
+          org: "test-org",
+          project: "test-project",
+          release: {
+            name: "release-2",
+            deploy: { env: "production" },
+          },
+        },
+        { buildTool: "webpack", loggerPrefix: "[sentry-webpack-plugin]" }
+      );
+
+      await managerA.createRelease();
+      await managerB.createRelease();
+
+      expect(mockCliNewDeploy).toHaveBeenCalledTimes(2);
+      expect(mockCliNewDeploy).toHaveBeenCalledWith("release-1", { env: "production" });
+      expect(mockCliNewDeploy).toHaveBeenCalledWith("release-2", { env: "production" });
+    });
+
+    it("should not create a deploy when deploy option is not set", async () => {
+      const manager = createSentryBuildPluginManager(
+        {
+          authToken: "test-token",
+          org: "test-org",
+          project: "test-project",
+          release: { name: "test-release" },
+        },
+        { buildTool: "webpack", loggerPrefix: "[sentry-webpack-plugin]" }
+      );
+
+      await manager.createRelease();
+
+      expect(mockCliNewDeploy).not.toHaveBeenCalled();
+    });
+  });
 });