diff --git a/.changeset/fuzzy-seas-fix.md b/.changeset/fuzzy-seas-fix.md
new file mode 100644
index 00000000..00a8c787
--- /dev/null
+++ b/.changeset/fuzzy-seas-fix.md
@@ -0,0 +1,5 @@
+---
+'@openai/agents-realtime': patch
+---
+
+fix: #633 fix a bug where tracingDisabled in realtime config does not work
diff --git a/packages/agents-realtime/src/openaiRealtimeBase.ts b/packages/agents-realtime/src/openaiRealtimeBase.ts
index 27e093ab..a7144de2 100644
--- a/packages/agents-realtime/src/openaiRealtimeBase.ts
+++ b/packages/agents-realtime/src/openaiRealtimeBase.ts
@@ -672,7 +672,7 @@ export abstract class OpenAIRealtimeBase
    *
    * @param tracingConfig - The tracing config to set. We don't support 'auto' here as the SDK will always configure a Workflow Name unless it exists
    */
-  protected _updateTracingConfig(tracingConfig: RealtimeTracingConfig) {
+  protected _updateTracingConfig(tracingConfig: RealtimeTracingConfig | null) {
     if (typeof this.#tracingConfig === 'undefined') {
       // treating it as default value
       this.#tracingConfig = null;
diff --git a/packages/agents-realtime/src/openaiRealtimeWebRtc.ts b/packages/agents-realtime/src/openaiRealtimeWebRtc.ts
index 19d5279b..b822e965 100644
--- a/packages/agents-realtime/src/openaiRealtimeWebRtc.ts
+++ b/packages/agents-realtime/src/openaiRealtimeWebRtc.ts
@@ -245,7 +245,11 @@ export class OpenAIRealtimeWebRTC
           if (parsed.type === 'session.created') {
             this._tracingConfig = parsed.session.tracing;
             // Trying to turn on tracing after the session is created
-            this._updateTracingConfig(userSessionConfig.tracing ?? 'auto');
+            const tracingConfig =
+              typeof userSessionConfig.tracing === 'undefined'
+                ? 'auto'
+                : userSessionConfig.tracing;
+            this._updateTracingConfig(tracingConfig);
           }
         });
 
diff --git a/packages/agents-realtime/src/openaiRealtimeWebsocket.ts b/packages/agents-realtime/src/openaiRealtimeWebsocket.ts
index d8715a41..3ee85c1c 100644
--- a/packages/agents-realtime/src/openaiRealtimeWebsocket.ts
+++ b/packages/agents-realtime/src/openaiRealtimeWebsocket.ts
@@ -308,7 +308,11 @@ export class OpenAIRealtimeWebSocket
       } else if (parsed.type === 'session.created') {
         this._tracingConfig = parsed.session.tracing;
         // Trying to turn on tracing after the session is created
-        this._updateTracingConfig(sessionConfig.tracing ?? 'auto');
+        const tracingConfig =
+          typeof sessionConfig.tracing === 'undefined'
+            ? 'auto'
+            : sessionConfig.tracing;
+        this._updateTracingConfig(tracingConfig);
       }
     });
 
diff --git a/packages/agents-realtime/src/realtimeSession.ts b/packages/agents-realtime/src/realtimeSession.ts
index f697e952..6815b38c 100644
--- a/packages/agents-realtime/src/realtimeSession.ts
+++ b/packages/agents-realtime/src/realtimeSession.ts
@@ -350,6 +350,8 @@ export class RealtimeSession<
       this.#context,
     );
 
+    // Realtime expects tracing to be explicitly null to disable it; leaving the previous config
+    // in place would otherwise continue emitting spans.
     const tracingConfig: RealtimeTracingConfig | null = this.options
       .tracingDisabled
       ? null
diff --git a/packages/agents-realtime/test/openaiRealtimeWebsocket.test.ts b/packages/agents-realtime/test/openaiRealtimeWebsocket.test.ts
index fa5216ec..c978ad70 100644
--- a/packages/agents-realtime/test/openaiRealtimeWebsocket.test.ts
+++ b/packages/agents-realtime/test/openaiRealtimeWebsocket.test.ts
@@ -194,6 +194,37 @@ describe('OpenAIRealtimeWebSocket', () => {
     expect(() => ws.mute(true)).toThrow('Mute is not supported');
   });
 
+  it('disables tracing when initial config sets tracing to null', async () => {
+    const updateSpy = vi.spyOn(
+      OpenAIRealtimeBase.prototype as any,
+      '_updateTracingConfig',
+    );
+    const ws = new OpenAIRealtimeWebSocket();
+    const connectPromise = ws.connect({
+      apiKey: 'ek',
+      model: 'm',
+      initialSessionConfig: {
+        tracing: null,
+      },
+    });
+    await vi.runAllTimersAsync();
+    await connectPromise;
+
+    lastFakeSocket!.emit('message', {
+      data: JSON.stringify({
+        type: 'session.created',
+        event_id: 'evt_1',
+        session: {
+          tracing: 'auto',
+        },
+      }),
+    });
+
+    expect(updateSpy).toHaveBeenCalled();
+    const lastCall = updateSpy.mock.calls.at(-1);
+    expect(lastCall?.[0]).toBeNull();
+  });
+
   it('sendAudio only sends when connected', async () => {
     const baseSpy = vi.spyOn(OpenAIRealtimeBase.prototype, 'sendAudio');
     const ws = new OpenAIRealtimeWebSocket();