diff --git a/src/TodoistApi.tasks.test.ts b/src/TodoistApi.tasks.test.ts
index 0060b73..1cc0ab1 100644
--- a/src/TodoistApi.tasks.test.ts
+++ b/src/TodoistApi.tasks.test.ts
@@ -14,6 +14,7 @@ import {
     ENDPOINT_REST_TASKS_FILTER,
     ENDPOINT_REST_TASKS_COMPLETED_BY_COMPLETION_DATE,
     ENDPOINT_REST_TASKS_COMPLETED_BY_DUE_DATE,
+    ENDPOINT_REST_TASKS_COMPLETED_SEARCH,
     ENDPOINT_SYNC_QUICK_ADD,
 } from './consts/endpoints'
 import { setupRestClientMock } from './testUtils/mocks'
@@ -430,4 +431,50 @@ describe('TodoistApi task endpoints', () => {
             ).rejects.toThrow()
         })
     })
+
+    describe('searchCompletedTasks', () => {
+        const DEFAULT_SEARCH_COMPLETED_TASKS_ARGS = {
+            query: 'buy milk',
+            cursor: null,
+            limit: 10,
+        }
+
+        test('calls get request with expected url', async () => {
+            const requestMock = setupRestClientMock({ items: [DEFAULT_TASK], nextCursor: null })
+            const api = getTarget()
+
+            await api.searchCompletedTasks(DEFAULT_SEARCH_COMPLETED_TASKS_ARGS)
+
+            expect(requestMock).toHaveBeenCalledTimes(1)
+            expect(requestMock).toHaveBeenCalledWith(
+                'GET',
+                getSyncBaseUri(),
+                ENDPOINT_REST_TASKS_COMPLETED_SEARCH,
+                DEFAULT_AUTH_TOKEN,
+                DEFAULT_SEARCH_COMPLETED_TASKS_ARGS,
+            )
+        })
+
+        test('returns result from rest client', async () => {
+            setupRestClientMock({ items: [DEFAULT_TASK], nextCursor: '789' })
+            const api = getTarget()
+
+            const response = await api.searchCompletedTasks(DEFAULT_SEARCH_COMPLETED_TASKS_ARGS)
+
+            expect(response).toEqual({
+                items: [DEFAULT_TASK],
+                nextCursor: '789',
+            })
+        })
+
+        test('validates task array in response', async () => {
+            const invalidTask = { ...DEFAULT_TASK, due: '2020-01-31' }
+            setupRestClientMock({ items: [invalidTask], nextCursor: null })
+            const api = getTarget()
+
+            await expect(
+                api.searchCompletedTasks(DEFAULT_SEARCH_COMPLETED_TASKS_ARGS),
+            ).rejects.toThrow()
+        })
+    })
 })
diff --git a/src/TodoistApi.ts b/src/TodoistApi.ts
index 8662603..7710207 100644
--- a/src/TodoistApi.ts
+++ b/src/TodoistApi.ts
@@ -44,6 +44,7 @@ import {
     GetCompletedTasksResponse,
     GetArchivedProjectsArgs,
     GetArchivedProjectsResponse,
+    SearchCompletedTasksArgs,
 } from './types/requests'
 import { request, isSuccess } from './restClient'
 import {
@@ -52,6 +53,7 @@ import {
     ENDPOINT_REST_TASKS_FILTER,
     ENDPOINT_REST_TASKS_COMPLETED_BY_COMPLETION_DATE,
     ENDPOINT_REST_TASKS_COMPLETED_BY_DUE_DATE,
+    ENDPOINT_REST_TASKS_COMPLETED_SEARCH,
     ENDPOINT_REST_PROJECTS,
     ENDPOINT_SYNC_QUICK_ADD,
     ENDPOINT_REST_TASK_CLOSE,
@@ -271,6 +273,29 @@ export class TodoistApi {
         }
     }
 
+    /**
+     * Searches completed tasks by query string.
+     *
+     * @param args - Parameters for searching, including the query string.
+     * @returns A promise that resolves to a paginated response of completed tasks.
+     */
+    async searchCompletedTasks(args: SearchCompletedTasksArgs): Promise<GetCompletedTasksResponse> {
+        const {
+            data: { items, nextCursor },
+        } = await request<GetCompletedTasksResponse>(
+            'GET',
+            this.syncApiBase,
+            ENDPOINT_REST_TASKS_COMPLETED_SEARCH,
+            this.authToken,
+            args,
+        )
+
+        return {
+            items: validateTaskArray(items),
+            nextCursor,
+        }
+    }
+
     /**
      * Creates a new task with the provided parameters.
      *
diff --git a/src/consts/endpoints.ts b/src/consts/endpoints.ts
index 9a1f5c4..d60e09d 100644
--- a/src/consts/endpoints.ts
+++ b/src/consts/endpoints.ts
@@ -23,6 +23,7 @@ export const ENDPOINT_REST_TASKS_COMPLETED_BY_COMPLETION_DATE =
     ENDPOINT_REST_TASKS + '/completed/by_completion_date'
 export const ENDPOINT_REST_TASKS_COMPLETED_BY_DUE_DATE =
     ENDPOINT_REST_TASKS + '/completed/by_due_date'
+export const ENDPOINT_REST_TASKS_COMPLETED_SEARCH = 'completed/search'
 export const ENDPOINT_REST_SECTIONS = 'sections'
 export const ENDPOINT_REST_LABELS = 'labels'
 export const ENDPOINT_REST_LABELS_SHARED = ENDPOINT_REST_LABELS + '/shared'
diff --git a/src/types/requests.ts b/src/types/requests.ts
index 1144bb2..f587603 100644
--- a/src/types/requests.ts
+++ b/src/types/requests.ts
@@ -98,6 +98,15 @@ export type GetCompletedTasksByDueDateArgs = {
     limit?: number
 }
 
+/**
+ * Arguments for searching completed tasks.
+ */
+export type SearchCompletedTasksArgs = {
+    query: string
+    cursor?: string | null
+    limit?: number
+}
+
 /**
  * @see https://todoist.com/api/v1/docs#tag/Tasks/operation/get_tasks_api_v1_tasks_get
  */