diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7800f22..ff71deb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,11 @@
 
+## [Unreleased]
+### Added
+- `retry_of` property is now automatically included in the `startTestItem`
+  request payload when `retry: true` and a previous attempt exists in the
+  retry chain. This allows the ReportPortal backend to link retry chains
+  efficiently, improving query performance for large test runs.
+
 ## [5.5.11] - 2026-05-22
 ### Added
 - Google Analytics improvements.
diff --git a/__tests__/report-portal-client.spec.js b/__tests__/report-portal-client.spec.js
index 4754279..afb5479 100644
--- a/__tests__/report-portal-client.spec.js
+++ b/__tests__/report-portal-client.spec.js
@@ -879,6 +879,102 @@ describe('ReportPortal javascript client', () => {
 
       expect(client.itemRetriesChainMap.get).toHaveBeenCalledWith('id1__name__');
     });
+
+    it('should include retry_of with the previous item UUID when retry is true', async () => {
+      const client = new RPClient({
+        apiKey: 'test',
+        endpoint: 'https://rp.us/api/v1',
+        project: 'tst',
+      });
+      const prevRealId = 'prev-item-uuid-1234';
+      const prevPromise = Promise.resolve({ id: prevRealId });
+
+      client.map = {
+        launchId: {
+          children: [],
+          finishSend: false,
+          promiseStart: Promise.resolve(),
+        },
+      };
+
+      const itemKey = client.calculateItemRetriesChainMapKey(
+        'launchId', undefined, 'My test', undefined,
+      );
+      client.itemRetriesChainMap.set(itemKey, prevPromise);
+
+      jest.spyOn(client.restClient, 'create').mockResolvedValue({ id: 'new-item-uuid' });
+      jest.spyOn(client, 'getUniqId').mockReturnValue('newTempId');
+
+      await client.startTestItem(
+        { name: 'My test', type: 'STEP', retry: true },
+        'launchId',
+      ).promise;
+
+      expect(client.restClient.create).toHaveBeenCalledWith(
+        expect.any(String),
+        expect.objectContaining({ retry_of: prevRealId }),
+      );
+    });
+
+    it('should not include retry_of when retry is true but no previous entry exists', async () => {
+      const client = new RPClient({
+        apiKey: 'test',
+        endpoint: 'https://rp.us/api/v1',
+        project: 'tst',
+      });
+      client.map = {
+        launchId: {
+          children: [],
+          finishSend: false,
+          promiseStart: Promise.resolve(),
+        },
+      };
+      jest.spyOn(client.restClient, 'create').mockResolvedValue({ id: 'new-item-uuid' });
+      jest.spyOn(client, 'getUniqId').mockReturnValue('newTempId');
+
+      await client.startTestItem(
+        { name: 'My test', type: 'STEP', retry: true },
+        'launchId',
+      ).promise;
+
+      expect(client.restClient.create).toHaveBeenCalledWith(
+        expect.any(String),
+        expect.not.objectContaining({ retry_of: expect.anything() }),
+      );
+    });
+
+    it('should not include retry_of when retry is false', async () => {
+      const client = new RPClient({
+        apiKey: 'test',
+        endpoint: 'https://rp.us/api/v1',
+        project: 'tst',
+      });
+      const prevPromise = Promise.resolve({ id: 'prev-item-uuid-1234' });
+      client.map = {
+        launchId: {
+          children: [],
+          finishSend: false,
+          promiseStart: Promise.resolve(),
+        },
+      };
+      const itemKey = client.calculateItemRetriesChainMapKey(
+        'launchId', undefined, 'My test', undefined,
+      );
+      client.itemRetriesChainMap.set(itemKey, prevPromise);
+
+      jest.spyOn(client.restClient, 'create').mockResolvedValue({ id: 'new-item-uuid' });
+      jest.spyOn(client, 'getUniqId').mockReturnValue('newTempId');
+
+      await client.startTestItem(
+        { name: 'My test', type: 'STEP', retry: false },
+        'launchId',
+      ).promise;
+
+      expect(client.restClient.create).toHaveBeenCalledWith(
+        expect.any(String),
+        expect.not.objectContaining({ retry_of: expect.anything() }),
+      );
+    });
   });
 
   describe('finishTestItem', () => {
diff --git a/index.d.ts b/index.d.ts
index fedd35d..46c684e 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -200,6 +200,18 @@ declare module '@reportportal/client-javascript' {
     startTime?: string | number;
     attributes?: Array<{ key?: string; value?: string } | string>;
     hasStats?: boolean;
+    /**
+     * Set to true when this item is a retry of a previous attempt.
+     * The client will automatically populate `retry_of` with the UUID of the
+     * previous attempt.
+     */
+    retry?: boolean;
+    /**
+     * UUID of the immediately-preceding retry attempt.
+     * Populated automatically by the client when `retry: true` and a previous
+     * attempt exists. Do not set manually.
+     */
+    retry_of?: string;
   }
 
   /**
diff --git a/lib/report-portal-client.js b/lib/report-portal-client.js
index 7adbb25..58e14f4 100644
--- a/lib/report-portal-client.js
+++ b/lib/report-portal-client.js
@@ -562,13 +562,16 @@ class RPClient {
     const tempId = this.getUniqId();
     this.map[tempId] = this.getNewItemObj((resolve, reject) => {
       (executionItemPromise || parentPromise).then(
-        () => {
+        (prevResponse) => {
           const realLaunchId = this.map[launchTempId].realId;
           let url = 'item/';
           if (parentTempId) {
             const realParentId = this.map[parentTempId].realId;
             url += `${realParentId}`;
           }
+          if (executionItemPromise && prevResponse?.id) {
+            testItemData.retry_of = prevResponse.id;
+          }
           testItemData.launchUuid = realLaunchId;
           this.logDebug(`Start test item with tempId ${tempId}`, testItemData);
           this.restClient.create(url, testItemData).then(
diff --git a/package-lock.json b/package-lock.json
index 0312957..46b051f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -6,7 +6,7 @@
   "packages": {
     "": {
       "name": "@reportportal/client-javascript",
-      "version": "5.5.10",
+      "version": "5.5.11",
       "license": "Apache-2.0",
       "dependencies": {
         "axios": "^1.15.2",