diff --git a/dev-packages/node-integration-tests/suites/tracing/openai/test.ts b/dev-packages/node-integration-tests/suites/tracing/openai/test.ts
index 754328af131a..4db70ae10643 100644
--- a/dev-packages/node-integration-tests/suites/tracing/openai/test.ts
+++ b/dev-packages/node-integration-tests/suites/tracing/openai/test.ts
@@ -1371,9 +1371,9 @@ describe('OpenAI integration', () => {
     });
   });
 
-  // Test for conversation ID support (Conversations API and previous_response_id)
+  // Conversation id: read from the Conversations API, not from `previous_response_id` chaining
   createEsmAndCjsTests(__dirname, 'scenario-conversation.mjs', 'instrument.mjs', (createRunner, test) => {
-    test('captures conversation ID from Conversations API and previous_response_id', async () => {
+    test('captures the conversation ID from the Conversations API and ignores previous_response_id', async () => {
       let receivedSpans: SerializedStreamedSpanContainer['items'] = [];
 
       await createRunner()
@@ -1445,47 +1445,20 @@ describe('OpenAI integration', () => {
         value: 'conv_689667905b048191b4740501625afd940c7533ace33a2dab',
       });
 
-      const unlinkedResponseSpan = spans.find(
+      // The unlinked call and the one chained with `previous_response_id` both carry no conversation id:
+      // a response id names one response, not the thread, so chaining does not group spans.
+      const unlinkedResponseSpans = spans.filter(
         span =>
           span.attributes[SENTRY_OP]?.value === 'gen_ai.chat' &&
           span.attributes[GEN_AI_REQUEST_MODEL]?.value === 'gpt-4' &&
           span.attributes[GEN_AI_CONVERSATION_ID] === undefined,
       );
-      expect(unlinkedResponseSpan!.status).toBe('ok');
-      expect(unlinkedResponseSpan!.attributes[SENTRY_OP]).toEqual({
-        type: 'string',
-        value: 'gen_ai.chat',
-      });
-      expect(unlinkedResponseSpan!.attributes[GEN_AI_CONVERSATION_ID]).toBeUndefined();
-
-      const previousResponseSpan = spans.find(
-        span => span.attributes[GEN_AI_CONVERSATION_ID]?.value === 'resp_mock_conv_123',
-      );
-      expect(previousResponseSpan!.status).toBe('ok');
-      expect(previousResponseSpan!.attributes[GEN_AI_OPERATION_NAME]).toEqual({
-        type: 'string',
-        value: 'chat',
-      });
-      expect(previousResponseSpan!.attributes[SENTRY_OP]).toEqual({
-        type: 'string',
-        value: 'gen_ai.chat',
-      });
-      expect(previousResponseSpan!.attributes[SENTRY_ORIGIN]).toEqual({
-        type: 'string',
-        value: 'auto.ai.openai',
-      });
-      expect(previousResponseSpan!.attributes[GEN_AI_PROVIDER_NAME]).toEqual({
-        type: 'string',
-        value: 'openai',
-      });
-      expect(previousResponseSpan!.attributes[GEN_AI_REQUEST_MODEL]).toEqual({
-        type: 'string',
-        value: 'gpt-4',
-      });
-      expect(previousResponseSpan!.attributes[GEN_AI_CONVERSATION_ID]).toEqual({
-        type: 'string',
-        value: 'resp_mock_conv_123',
-      });
+      expect(unlinkedResponseSpans).toHaveLength(2);
+      for (const span of unlinkedResponseSpans) {
+        expect(span.status).toBe('ok');
+        expect(span.attributes[GEN_AI_RESPONSE_ID]).toEqual({ type: 'string', value: 'resp_mock_conv_123' });
+      }
+      expect(spans.some(span => span.attributes[GEN_AI_CONVERSATION_ID]?.value === 'resp_mock_conv_123')).toBe(false);
 
       const rawConversationSpan = spans.find(
         span => span.name === 'chat' && span.attributes[GEN_AI_CONVERSATION_ID] === undefined,
diff --git a/packages/server-utils/src/ai/openai/utils.ts b/packages/server-utils/src/ai/openai/utils.ts
index 49b39eb85013..3f6afeac1c44 100644
--- a/packages/server-utils/src/ai/openai/utils.ts
+++ b/packages/server-utils/src/ai/openai/utils.ts
@@ -166,20 +166,13 @@ export function addResponseAttributes(span: Span, result: unknown, recordOutputs
 }
 
 /**
- * Extract conversation ID from request parameters
- * Supports both Conversations API and previous_response_id chaining
+ * Extract the Conversations API id (`conversation: "conv_..."`) from request parameters.
+ * `previous_response_id` is deliberately not read: it names the previous response, so it changes on
+ * every turn and cannot group a conversation's spans.
  * @see https://platform.openai.com/docs/guides/conversation-state
  */
 function extractConversationId(params: Record<string, unknown>): string | undefined {
-  // Conversations API: conversation parameter (e.g., "conv_...")
-  if ('conversation' in params && typeof params.conversation === 'string') {
-    return params.conversation;
-  }
-  // Responses chaining: previous_response_id links to parent response
-  if ('previous_response_id' in params && typeof params.previous_response_id === 'string') {
-    return params.previous_response_id;
-  }
-  return undefined;
+  return 'conversation' in params && typeof params.conversation === 'string' ? params.conversation : undefined;
 }
 
 /**
diff --git a/packages/server-utils/test/ai/lib/tracing/openai-conversation-id.test.ts b/packages/server-utils/test/ai/lib/tracing/openai-conversation-id.test.ts
new file mode 100644
index 000000000000..b7936ad86a54
--- /dev/null
+++ b/packages/server-utils/test/ai/lib/tracing/openai-conversation-id.test.ts
@@ -0,0 +1,52 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import { GEN_AI_CONVERSATION_ID, GEN_AI_RESPONSE_ID } from '@sentry/conventions/attributes';
+import { getMainCarrier, setCurrentClient, spanToStaticSpanJSON } from '@sentry/core';
+import type { Span } from '@sentry/core';
+import { instrumentOpenAiClient } from '../../../../src/ai/openai';
+import { getDefaultTestClientOptions, TestClient } from '../../../mocks/client';
+
+describe('instrumentOpenAiClient conversation id', () => {
+  let endedSpans: Span[];
+
+  beforeEach(() => {
+    getMainCarrier().__SENTRY__ = undefined;
+    const client = new TestClient(
+      getDefaultTestClientOptions({ dsn: 'https://public@dsn.ingest.sentry.io/1337', tracesSampleRate: 1 }),
+    );
+    setCurrentClient(client);
+    client.init();
+    endedSpans = [];
+    client.on('spanEnd', span => endedSpans.push(span));
+  });
+
+  afterEach(() => {
+    getMainCarrier().__SENTRY__ = undefined;
+  });
+
+  function responsesClient(): { responses: { create: ReturnType<typeof vi.fn> } } {
+    return {
+      responses: {
+        create: vi.fn().mockResolvedValue({ id: 'resp_2', object: 'response', model: 'gpt-4', output: [] }),
+      },
+    };
+  }
+
+  function data(): Record<string, unknown> {
+    return spanToStaticSpanJSON(endedSpans[0]!).data ?? {};
+  }
+
+  it('reads the Conversations API id from the `conversation` parameter', async () => {
+    const instrumented = instrumentOpenAiClient(responsesClient());
+    await instrumented.responses.create({ model: 'gpt-4', input: 'hi', conversation: 'conv_abc' });
+
+    expect(data()[GEN_AI_CONVERSATION_ID]).toBe('conv_abc');
+  });
+
+  it('does not treat `previous_response_id` chaining as a conversation id', async () => {
+    const instrumented = instrumentOpenAiClient(responsesClient());
+    await instrumented.responses.create({ model: 'gpt-4', input: 'hi', previous_response_id: 'resp_1' });
+
+    expect(data()[GEN_AI_CONVERSATION_ID]).toBeUndefined();
+    expect(data()[GEN_AI_RESPONSE_ID]).toBe('resp_2');
+  });
+});