diff --git a/docs/src/test-reporter-api/class-testresult.md b/docs/src/test-reporter-api/class-testresult.md
index f540c5e697..7674ac333d 100644
--- a/docs/src/test-reporter-api/class-testresult.md
+++ b/docs/src/test-reporter-api/class-testresult.md
@@ -78,3 +78,9 @@ List of steps inside this test run.
 Index of the worker where the test was run. If the test was not run a single time, for example when the user interrupted testing, the only result will have a `workerIndex` equal to `-1`.
 
 Learn more about [parallelism and sharding](../test-parallel.md) with Playwright Test.
+
+## property: TestResult.parallelIndex
+* since: v1.30
+- type: <[int]>
+
+The index of the worker between `0` and `workers - 1`. It is guaranteed that workers running at the same time have a different `parallelIndex`.
diff --git a/packages/playwright-test/src/dispatcher.ts b/packages/playwright-test/src/dispatcher.ts
index cced1404fd..0ff95225db 100644
--- a/packages/playwright-test/src/dispatcher.ts
+++ b/packages/playwright-test/src/dispatcher.ts
@@ -199,6 +199,7 @@ export class Dispatcher {
       const data = this._testById.get(params.testId)!;
       const result = data.test._appendTestResult();
       data.resultByWorkerIndex.set(worker.workerIndex, { result, stepStack: new Set(), steps: new Map() });
+      result.parallelIndex = worker.parallelIndex;
       result.workerIndex = worker.workerIndex;
       result.startTime = new Date(params.startWallTime);
       this._reporter.onTestBegin?.(data.test, result);
@@ -495,7 +496,7 @@ let lastWorkerIndex = 0;
 class Worker extends EventEmitter {
   private process: child_process.ChildProcess;
   private _hash: string;
-  private parallelIndex: number;
+  readonly parallelIndex: number;
   readonly workerIndex: number;
   private _didSendStop = false;
   private _didFail = false;
diff --git a/packages/playwright-test/src/test.ts b/packages/playwright-test/src/test.ts
index 594b6df42a..cb490f4edf 100644
--- a/packages/playwright-test/src/test.ts
+++ b/packages/playwright-test/src/test.ts
@@ -212,6 +212,7 @@ export class TestCase extends Base implements reporterTypes.TestCase {
   _appendTestResult(): reporterTypes.TestResult {
     const result: reporterTypes.TestResult = {
       retry: this.results.length,
+      parallelIndex: -1,
       workerIndex: -1,
       duration: 0,
       startTime: new Date(),
diff --git a/packages/playwright-test/types/testReporter.d.ts b/packages/playwright-test/types/testReporter.d.ts
index 76af5e52b1..f29a4e4b21 100644
--- a/packages/playwright-test/types/testReporter.d.ts
+++ b/packages/playwright-test/types/testReporter.d.ts
@@ -282,7 +282,13 @@ export interface TestResult {
    *
    * Learn more about [parallelism and sharding](https://playwright.dev/docs/test-parallel) with Playwright Test.
    */
-  workerIndex: number;}
+  workerIndex: number;
+
+  /**
+   * The index of the worker between `0` and `workers - 1`. It is guaranteed that workers running at the same time have
+   * a different `parallelIndex`.
+   */
+  parallelIndex: number;}
 
 /**
  * Result of the full test run.
diff --git a/tests/playwright-test/reporter.spec.ts b/tests/playwright-test/reporter.spec.ts
index b424923368..264265db22 100644
--- a/tests/playwright-test/reporter.spec.ts
+++ b/tests/playwright-test/reporter.spec.ts
@@ -607,6 +607,29 @@ var import_test = __toModule(require("@playwright/test"));
   expect(result.output).toContain('a.spec.ts');
 });
 
+test('parallelIndex is presented in onTestEnd', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'reporter.ts': `
+    class Reporter {
+      onTestEnd(test, result) {
+        console.log('parallelIndex: ' + result.parallelIndex)
+      }
+    }
+    module.exports = Reporter;`,
+    'playwright.config.ts': `
+      module.exports = {
+        reporter: './reporter',
+      };
+    `,
+    'a.spec.js': `
+      pwt.test('test', () => {});
+    `,
+  }, { 'reporter': '', 'workers': 1 });
+
+  expect(result.output).toContain('parallelIndex: 0');
+});
+
+
 function stripEscapedAscii(str: string) {
   return str.replace(/\\u00[a-z0-9][a-z0-9]\[[^m]+m/g, '');
 }