diff --git a/inspector.go b/inspector.go
index 61a6a48..c48ec83 100644
--- a/inspector.go
+++ b/inspector.go
@@ -364,10 +364,32 @@ func (i *Inspector) ListActiveTasks(qname string, opts ...ListOption) ([]*TaskIn
 	return tasks, nil
 }
 
-// TODO: comment
+// ListAggregatingTasks retrieves scheduled tasks from the specified group.
+//
+// By default, it retrieves the first 30 tasks.
 func (i *Inspector) ListAggregatingTasks(qname, gname string, opts ...ListOption) ([]*TaskInfo, error) {
-	// TODO: Implement this with TDD
-	return nil, nil
+	if err := base.ValidateQueueName(qname); err != nil {
+		return nil, fmt.Errorf("asynq: %v", err)
+	}
+	opt := composeListOptions(opts...)
+	pgn := rdb.Pagination{Size: opt.pageSize, Page: opt.pageNum - 1}
+	infos, err := i.rdb.ListAggregating(qname, gname, pgn)
+	switch {
+	case errors.IsQueueNotFound(err):
+		return nil, fmt.Errorf("asynq: %w", ErrQueueNotFound)
+	case err != nil:
+		return nil, fmt.Errorf("asynq: %v", err)
+	}
+	var tasks []*TaskInfo
+	for _, i := range infos {
+		tasks = append(tasks, newTaskInfo(
+			i.Message,
+			i.State,
+			i.NextProcessAt,
+			i.Result,
+		))
+	}
+	return tasks, nil
 }
 
 // ListScheduledTasks retrieves scheduled tasks from the specified queue.
diff --git a/inspector_test.go b/inspector_test.go
index 25ce538..c406528 100644
--- a/inspector_test.go
+++ b/inspector_test.go
@@ -1121,6 +1121,106 @@ func TestInspectorListCompletedTasks(t *testing.T) {
 	}
 }
 
+func TestInspectorListAggregatingTasks(t *testing.T) {
+	r := setup(t)
+	defer r.Close()
+	now := time.Now()
+
+	m1 := h.NewTaskMessageBuilder().SetType("task1").SetQueue("default").SetGroup("group1").Build()
+	m2 := h.NewTaskMessageBuilder().SetType("task2").SetQueue("default").SetGroup("group1").Build()
+	m3 := h.NewTaskMessageBuilder().SetType("task3").SetQueue("default").SetGroup("group1").Build()
+	m4 := h.NewTaskMessageBuilder().SetType("task4").SetQueue("default").SetGroup("group2").Build()
+	m5 := h.NewTaskMessageBuilder().SetType("task5").SetQueue("custom").SetGroup("group1").Build()
+
+	inspector := NewInspector(getRedisConnOpt(t))
+
+	fxt := struct {
+		tasks     []*h.TaskSeedData
+		allQueues []string
+		allGroups map[string][]string
+		groups    map[string][]*redis.Z
+	}{
+		tasks: []*h.TaskSeedData{
+			{Msg: m1, State: base.TaskStateAggregating},
+			{Msg: m2, State: base.TaskStateAggregating},
+			{Msg: m3, State: base.TaskStateAggregating},
+			{Msg: m4, State: base.TaskStateAggregating},
+			{Msg: m5, State: base.TaskStateAggregating},
+		},
+		allQueues: []string{"default", "custom"},
+		allGroups: map[string][]string{
+			base.AllGroups("default"): {"group1", "group2"},
+			base.AllGroups("custom"):  {"group1"},
+		},
+		groups: map[string][]*redis.Z{
+			base.GroupKey("default", "group1"): {
+				{Member: m1.ID, Score: float64(now.Add(-30 * time.Second).Unix())},
+				{Member: m2.ID, Score: float64(now.Add(-20 * time.Second).Unix())},
+				{Member: m3.ID, Score: float64(now.Add(-10 * time.Second).Unix())},
+			},
+			base.GroupKey("default", "group2"): {
+				{Member: m4.ID, Score: float64(now.Add(-30 * time.Second).Unix())},
+			},
+			base.GroupKey("custom", "group1"): {
+				{Member: m5.ID, Score: float64(now.Add(-30 * time.Second).Unix())},
+			},
+		},
+	}
+
+	tests := []struct {
+		desc  string
+		qname string
+		gname string
+		want  []*TaskInfo
+	}{
+		{
+			desc:  "default queue group1",
+			qname: "default",
+			gname: "group1",
+			want: []*TaskInfo{
+				createAggregatingTaskInfo(m1),
+				createAggregatingTaskInfo(m2),
+				createAggregatingTaskInfo(m3),
+			},
+		},
+		{
+			desc:  "custom queue group1",
+			qname: "custom",
+			gname: "group1",
+			want: []*TaskInfo{
+				createAggregatingTaskInfo(m5),
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		h.FlushDB(t, r)
+		h.SeedTasks(t, r, fxt.tasks)
+		h.SeedRedisSet(t, r, base.AllQueues, fxt.allQueues)
+		h.SeedRedisSets(t, r, fxt.allGroups)
+		h.SeedRedisZSets(t, r, fxt.groups)
+
+		t.Run(tc.desc, func(t *testing.T) {
+			got, err := inspector.ListAggregatingTasks(tc.qname, tc.gname)
+			if err != nil {
+				t.Fatalf("ListAggregatingTasks returned error: %v", err)
+			}
+
+			cmpOpts := []cmp.Option{
+				cmpopts.EquateApproxTime(2 * time.Second),
+				cmp.AllowUnexported(TaskInfo{}),
+			}
+			if diff := cmp.Diff(tc.want, got, cmpOpts...); diff != "" {
+				t.Errorf("ListAggregatingTasks = %v, want = %v; (-want,+got)\n%s", got, tc.want, diff)
+			}
+		})
+	}
+}
+
+func createAggregatingTaskInfo(msg *base.TaskMessage) *TaskInfo {
+	return newTaskInfo(msg, base.TaskStateAggregating, time.Time{}, nil)
+}
+
 func TestInspectorListPagination(t *testing.T) {
 	// Create 100 tasks.
 	var msgs []*base.TaskMessage
@@ -1222,6 +1322,9 @@ func TestInspectorListTasksQueueNotFoundError(t *testing.T) {
 		if _, err := inspector.ListCompletedTasks(tc.qname); !errors.Is(err, tc.wantErr) {
 			t.Errorf("ListCompletedTasks(%q) returned error %v, want %v", tc.qname, err, tc.wantErr)
 		}
+		if _, err := inspector.ListAggregatingTasks(tc.qname, "mygroup"); !errors.Is(err, tc.wantErr) {
+			t.Errorf("ListAggregatingTasks(%q, \"mygroup\") returned error %v, want %v", tc.qname, err, tc.wantErr)
+		}
 	}
 }