diff --git a/CHANGELOG.md b/CHANGELOG.md
index 470055e0b8c..1ed675222b9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -86,6 +86,7 @@ Docs: https://docs.openclaw.ai
 - Browser/security: require `operator.admin` for the `browser.request` gateway method, matching the host/browser-node control authority exposed by that route. Thanks @RichardCao.
 - Browser/profiles: allow local managed profiles to override `browser.executablePath`, so different profiles can launch different Chromium-based browsers. Thanks @nobrainer-tech.
 - Agents/replay: repair displaced or missing tool results before strict provider replay, use Codex-compatible `aborted` outputs for OpenAI Responses history, and drop partial aborted/error transport turns before retries.
+- Browser/startup: deduplicate concurrent lazy-start calls per profile so simultaneous browser tool requests no longer race into duplicate Chrome launches and `PortInUseError`. (#61772) Thanks @sukhdeepjohar.
 - Browser/profiles: recover from stale Chromium `Singleton*` profile locks after crashes or host moves by clearing dead/foreign locks and retrying launch once. Thanks @seanc-dev.
 - Reply media: allow sandboxed replies to deliver OpenClaw-managed `media/outbound` and `media/tool-*` attachments without treating them as sandbox escapes, while keeping alias-escape checks on the managed media root. Fixes #71138. Thanks @mayor686, @truffle-dev, and @neeravmakwana.
 - CLI/agent: keep `openclaw agent --json` stdout reserved for the JSON response by routing gateway, plugin, and embedded-fallback diagnostics to stderr before execution starts. Fixes #71319.
diff --git a/extensions/browser/src/browser/server-context.availability.ts b/extensions/browser/src/browser/server-context.availability.ts
index e72cab21a3f..27bc09f17fd 100644
--- a/extensions/browser/src/browser/server-context.availability.ts
+++ b/extensions/browser/src/browser/server-context.availability.ts
@@ -200,7 +200,9 @@ export function createProfileAvailability({
     throw new BrowserProfileUnavailableError(formatChromeMcpAttachFailure(lastError));
   };
 
-  const ensureBrowserAvailable = async (): Promise<void> => {
+  let inflightEnsureBrowserAvailable: Promise<void> | null = null;
+
+  const ensureBrowserAvailableOnce = async (): Promise<void> => {
     await reconcileProfileRuntime();
     if (capabilities.usesChromeMcp) {
       if (profile.userDataDir && !fs.existsSync(profile.userDataDir)) {
@@ -305,6 +307,16 @@ export function createProfileAvailability({
     }
   };
 
+  const ensureBrowserAvailable = async (): Promise<void> => {
+    if (inflightEnsureBrowserAvailable) {
+      return inflightEnsureBrowserAvailable;
+    }
+    inflightEnsureBrowserAvailable = ensureBrowserAvailableOnce().finally(() => {
+      inflightEnsureBrowserAvailable = null;
+    });
+    return inflightEnsureBrowserAvailable;
+  };
+
   const stopRunningBrowser = async (): Promise<{ stopped: boolean }> => {
     await reconcileProfileRuntime();
     if (capabilities.usesChromeMcp) {
diff --git a/extensions/browser/src/browser/server-context.ensure-browser-available.waits-for-cdp-ready.test.ts b/extensions/browser/src/browser/server-context.ensure-browser-available.waits-for-cdp-ready.test.ts
index b6d64a9d511..9a044053834 100644
--- a/extensions/browser/src/browser/server-context.ensure-browser-available.waits-for-cdp-ready.test.ts
+++ b/extensions/browser/src/browser/server-context.ensure-browser-available.waits-for-cdp-ready.test.ts
@@ -88,6 +88,42 @@ describe("browser server-context ensureBrowserAvailable", () => {
     expect(stopOpenClawChrome).toHaveBeenCalledTimes(1);
   });
 
+  it("deduplicates concurrent lazy-start calls to prevent PortInUseError", async () => {
+    const { launchOpenClawChrome, stopOpenClawChrome, isChromeCdpReady, profile } =
+      setupEnsureBrowserAvailableHarness();
+    isChromeCdpReady.mockResolvedValue(true);
+    mockLaunchedChrome(launchOpenClawChrome, 456);
+
+    const first = profile.ensureBrowserAvailable();
+    const second = profile.ensureBrowserAvailable();
+    await vi.advanceTimersByTimeAsync(100);
+    await expect(Promise.all([first, second])).resolves.toEqual([undefined, undefined]);
+
+    expect(launchOpenClawChrome).toHaveBeenCalledTimes(1);
+    expect(stopOpenClawChrome).not.toHaveBeenCalled();
+  });
+
+  it("clears the concurrent lazy-start guard after launch failure", async () => {
+    const { launchOpenClawChrome, stopOpenClawChrome, isChromeCdpReady, profile } =
+      setupEnsureBrowserAvailableHarness();
+    isChromeCdpReady.mockResolvedValue(true);
+    launchOpenClawChrome.mockRejectedValueOnce(
+      new Error("PortInUseError: listen EADDRINUSE 127.0.0.1:18800"),
+    );
+
+    const first = profile.ensureBrowserAvailable();
+    const second = profile.ensureBrowserAvailable();
+    await expect(Promise.all([first, second])).rejects.toThrow("PortInUseError");
+
+    mockLaunchedChrome(launchOpenClawChrome, 789);
+    const retry = profile.ensureBrowserAvailable();
+    await vi.advanceTimersByTimeAsync(100);
+    await expect(retry).resolves.toBeUndefined();
+
+    expect(launchOpenClawChrome).toHaveBeenCalledTimes(2);
+    expect(stopOpenClawChrome).not.toHaveBeenCalled();
+  });
+
   it("reuses a pre-existing loopback browser after an initial short probe miss", async () => {
     const { launchOpenClawChrome, stopOpenClawChrome, isChromeCdpReady, profile, state } =
       setupEnsureBrowserAvailableHarness();