diff --git a/packages/astro/src/integration/index.ts b/packages/astro/src/integration/index.ts
index 66b5de50861b..76bae75d5973 100644
--- a/packages/astro/src/integration/index.ts
+++ b/packages/astro/src/integration/index.ts
@@ -248,7 +248,8 @@ export const sentryAstro = (options: SentryOptions = {}): AstroIntegration => {
         if (isSSR && shouldAddMiddleware) {
           addMiddleware({
             order: 'pre',
-            entrypoint: serverInitSnippet ? SENTRY_MIDDLEWARE_MODULE : '@sentry/astro/middleware',
+            entrypoint:
+              serverInitSnippet && !isCloudflareWorkers ? SENTRY_MIDDLEWARE_MODULE : '@sentry/astro/middleware',
           });
         }
       },
diff --git a/packages/astro/src/server/sdk.ts b/packages/astro/src/server/sdk.ts
index 557c1b7812d7..98910a1db2fd 100644
--- a/packages/astro/src/server/sdk.ts
+++ b/packages/astro/src/server/sdk.ts
@@ -4,11 +4,21 @@ import { applySdkMetadata } from '@sentry/core';
 import type { NodeClient, NodeOptions } from '@sentry/node';
 import { init as initNodeSdk } from '@sentry/node';
 
+declare const EdgeRuntime: string | undefined;
+declare const Deno: unknown;
+declare const Netlify: unknown;
+
 /**
  *
  * @param options
  */
 export function init(options: NodeOptions): NodeClient | undefined {
+  // With `edgeMiddleware` enabled, Vercel and Netlify bundle our middleware (which imports the
+  // server init) into a separate edge function, where the Node SDK can't run.
+  if (isEdgeRuntime()) {
+    return undefined;
+  }
+
   const opts = {
     ...options,
   };
@@ -26,3 +36,8 @@ export function init(options: NodeOptions): NodeClient | undefined {
 
   return initNodeSdk(opts);
 }
+
+function isEdgeRuntime(): boolean {
+  // Netlify also defines the `Netlify` global in its Node functions, so only Deno + Netlify is its edge.
+  return typeof EdgeRuntime === 'string' || (typeof Netlify !== 'undefined' && typeof Deno !== 'undefined');
+}
diff --git a/packages/astro/test/integration/index.files.test.ts b/packages/astro/test/integration/index.files.test.ts
index 125333ede7be..05cf524543b8 100644
--- a/packages/astro/test/integration/index.files.test.ts
+++ b/packages/astro/test/integration/index.files.test.ts
@@ -37,4 +37,22 @@ describe('sentryAstro integration', () => {
       /^import ".*\/sentry.server.config.js"/,
     );
   });
+
+  it('imports the default server init file from the middleware entrypoint', async () => {
+    const addMiddleware = vi.fn();
+    const updateConfig = vi.fn();
+    const setup = sentryAstro({}).hooks['astro:config:setup'] as (params: unknown) => Promise<void>;
+
+    await setup({ updateConfig, injectScript, addMiddleware, config: { output: 'server' } });
+
+    expect(addMiddleware).toHaveBeenCalledWith({
+      order: 'pre',
+      entrypoint: 'virtual:@sentry/astro/middleware',
+    });
+
+    const plugin = updateConfig.mock.calls
+      .flatMap(([updatedConfig]) => updatedConfig.vite?.plugins ?? [])
+      .find((vitePlugin: { name?: string }) => vitePlugin?.name === 'sentry-astro-server-init');
+    expect(plugin.load('\0virtual:@sentry/astro/server-init')).toMatch(/^import ".*\/sentry.server.config.js";$/);
+  });
 });
diff --git a/packages/astro/test/integration/index.test.ts b/packages/astro/test/integration/index.test.ts
index 62481501bd23..870c28dc5b30 100644
--- a/packages/astro/test/integration/index.test.ts
+++ b/packages/astro/test/integration/index.test.ts
@@ -690,6 +690,24 @@ describe('sentryAstro integration', () => {
     });
   });
 
+  it('keeps the default middleware entrypoint for the Cloudflare Workers adapter', async () => {
+    const addMiddleware = vi.fn();
+    const setup = sentryAstro({ serverInitPath: 'my-server-init-path.js' }).hooks['astro:config:setup'] as (
+      params: unknown,
+    ) => Promise<void>;
+
+    await setup({
+      ...baseConfigHookObject,
+      config: { output: 'server', adapter: { name: '@astrojs/cloudflare' } },
+      addMiddleware,
+      updateConfig,
+      injectScript,
+    });
+
+    expect(addMiddleware).toHaveBeenCalledWith({ order: 'pre', entrypoint: '@sentry/astro/middleware' });
+    expect(getServerInit(updateConfig)).toContain('my-server-init-path.js');
+  });
+
   it('runs the server init once, from SSR pages and the middleware alike, so requests that render no page find a client', async () => {
     const integration = sentryAstro({});
     const updateConfig = vi.fn();
diff --git a/packages/astro/test/server/sdk.test.ts b/packages/astro/test/server/sdk.test.ts
index 6de7cab9f38e..e9d15f50cb7f 100644
--- a/packages/astro/test/server/sdk.test.ts
+++ b/packages/astro/test/server/sdk.test.ts
@@ -10,10 +10,42 @@ describe('Sentry server SDK', () => {
   describe('init', () => {
     afterEach(() => {
       vi.clearAllMocks();
+      vi.unstubAllGlobals();
 
       getMainCarrier().__SENTRY__ = undefined;
     });
 
+    it("doesn't initialize the SDK in the Vercel Edge runtime", () => {
+      vi.stubGlobal('EdgeRuntime', 'edge-runtime');
+
+      expect(init({})).toBeUndefined();
+      expect(nodeInit).not.toHaveBeenCalled();
+    });
+
+    it("doesn't initialize the SDK in Netlify edge functions", () => {
+      vi.stubGlobal('Netlify', {});
+      vi.stubGlobal('Deno', {});
+
+      expect(init({})).toBeUndefined();
+      expect(nodeInit).not.toHaveBeenCalled();
+    });
+
+    it('initializes the SDK in Netlify Node functions', () => {
+      vi.stubGlobal('Netlify', {});
+
+      init({});
+
+      expect(nodeInit).toHaveBeenCalledTimes(1);
+    });
+
+    it('initializes the SDK in Deno', () => {
+      vi.stubGlobal('Deno', {});
+
+      init({});
+
+      expect(nodeInit).toHaveBeenCalledTimes(1);
+    });
+
     it('adds Astro metadata to the SDK options', () => {
       expect(nodeInit).not.toHaveBeenCalled();