diff --git a/src/api.ts b/src/api.ts
index c3dbb428..282e1003 100644
--- a/src/api.ts
+++ b/src/api.ts
@@ -564,8 +564,8 @@ export class Api {
   /**
    * Set assignee for an issue
    *
-   * @param issue Issue to set milestone for
-   * @param userId ID of the milestone to set for the issue
+   * @param issue Issue to set assignee for
+   * @param userId ID of the assignee to set for the issue
    */
   public async setAssigneeForIssue(issue: Issue, userId: number): Promise<Issue> {
     return this.makeGitLabAPIRequest(
@@ -576,6 +576,21 @@ export class Api {
     ) as Promise<Issue>;
   }
 
+  /**
+   * Set assignee for an merge request
+   *
+   * @param mergeRequest Merge request to set assignee for
+   * @param userId ID of the assignee to set for the merge request
+   */
+  public async setAssigneeForMergeRequest(mergeRequest: MergeRequest, userId: number): Promise<MergeRequest> {
+    return this.makeGitLabAPIRequest(
+      `projects/${mergeRequest.project_id}/merge_requests/${mergeRequest.iid}?assignee_ids=${userId}`,
+      {
+        method: 'PUT',
+      },
+    ) as Promise<MergeRequest>;
+  }
+
   /**
    * Set milestone for an issue
    *