diff --git a/inspector.go b/inspector.go
index 8a364a2..61a6a48 100644
--- a/inspector.go
+++ b/inspector.go
@@ -43,7 +43,32 @@ func (i *Inspector) Queues() ([]string, error) {
 	return i.rdb.AllQueues()
 }
 
-// QueueInfo represents a state of queues at a certain time.
+// Groups returns a list of all groups within the given queue.
+func (i *Inspector) Groups(qname string) ([]*GroupInfo, error) {
+	stats, err := i.rdb.GroupStats(qname)
+	if err != nil {
+		return nil, err
+	}
+	var res []*GroupInfo
+	for _, s := range stats {
+		res = append(res, &GroupInfo{
+			Group: s.Group,
+			Size:  s.Size,
+		})
+	}
+	return res, nil
+}
+
+// GroupInfo represents a state of a group at a cerntain time.
+type GroupInfo struct {
+	// Name of the group.
+	Group string
+
+	// Size is the total number of tasks in the group.
+	Size int
+}
+
+// QueueInfo represents a state of a queue at a certain time.
 type QueueInfo struct {
 	// Name of the queue.
 	Queue string
@@ -339,6 +364,12 @@ func (i *Inspector) ListActiveTasks(qname string, opts ...ListOption) ([]*TaskIn
 	return tasks, nil
 }
 
+// TODO: comment
+func (i *Inspector) ListAggregatingTasks(qname, gname string, opts ...ListOption) ([]*TaskInfo, error) {
+	// TODO: Implement this with TDD
+	return nil, nil
+}
+
 // ListScheduledTasks retrieves scheduled tasks from the specified queue.
 // Tasks are sorted by NextProcessAt in ascending order.
 //
@@ -505,6 +536,12 @@ func (i *Inspector) DeleteAllCompletedTasks(qname string) (int, error) {
 	return int(n), err
 }
 
+// TODO: comment
+func (i *Inspector) DeleteAllAggregatingTasks(qname, gname string) (int, error) {
+	// TODO: implement this
+	return 0, nil
+}
+
 // DeleteTask deletes a task with the given id from the given queue.
 // The task needs to be in pending, scheduled, retry, or archived state,
 // otherwise DeleteTask will return an error.
@@ -612,6 +649,12 @@ func (i *Inspector) ArchiveAllRetryTasks(qname string) (int, error) {
 	return int(n), err
 }
 
+// TODO: comment
+func (i *Inspector) ArchiveAllAggregatingTasks(qname, gname string) (int, error) {
+	// TODO: implement this
+	return 0, nil
+}
+
 // ArchiveTask archives a task with the given id in the given queue.
 // The task needs to be in pending, scheduled, or retry state, otherwise ArchiveTask
 // will return an error.
diff --git a/inspector_test.go b/inspector_test.go
index ff8add0..25ce538 100644
--- a/inspector_test.go
+++ b/inspector_test.go
@@ -12,6 +12,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/go-redis/redis/v8"
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/google/uuid"
@@ -3323,3 +3324,99 @@ func TestParseOption(t *testing.T) {
 		})
 	}
 }
+
+func TestInspectorGroups(t *testing.T) {
+	r := setup(t)
+	defer r.Close()
+	inspector := NewInspector(getRedisConnOpt(t))
+
+	m1 := h.NewTaskMessageBuilder().SetGroup("group1").Build()
+	m2 := h.NewTaskMessageBuilder().SetGroup("group1").Build()
+	m3 := h.NewTaskMessageBuilder().SetGroup("group1").Build()
+	m4 := h.NewTaskMessageBuilder().SetGroup("group2").Build()
+	m5 := h.NewTaskMessageBuilder().SetQueue("custom").SetGroup("group1").Build()
+	m6 := h.NewTaskMessageBuilder().SetQueue("custom").SetGroup("group1").Build()
+
+	now := time.Now()
+
+	fixtures := struct {
+		tasks     []*h.TaskSeedData
+		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},
+		},
+		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(-10 * time.Second).Unix())},
+				{Member: m2.ID, Score: float64(now.Add(-20 * time.Second).Unix())},
+				{Member: m3.ID, Score: float64(now.Add(-30 * time.Second).Unix())},
+			},
+			base.GroupKey("default", "group2"): {
+				{Member: m4.ID, Score: float64(now.Add(-20 * time.Second).Unix())},
+			},
+			base.GroupKey("custom", "group1"): {
+				{Member: m5.ID, Score: float64(now.Add(-10 * time.Second).Unix())},
+				{Member: m6.ID, Score: float64(now.Add(-20 * time.Second).Unix())},
+			},
+		},
+	}
+
+	tests := []struct {
+		desc  string
+		qname string
+		want  []*GroupInfo
+	}{
+		{
+			desc:  "default queue groups",
+			qname: "default",
+			want: []*GroupInfo{
+				{Group: "group1", Size: 3},
+				{Group: "group2", Size: 1},
+			},
+		},
+		{
+			desc:  "custom queue groups",
+			qname: "custom",
+			want: []*GroupInfo{
+				{Group: "group1", Size: 2},
+			},
+		},
+	}
+
+	var sortGroupInfosOpt = cmp.Transformer(
+		"SortGroupInfos",
+		func(in []*GroupInfo) []*GroupInfo {
+			out := append([]*GroupInfo(nil), in...)
+			sort.Slice(out, func(i, j int) bool {
+				return out[i].Group < out[j].Group
+			})
+			return out
+		})
+
+	for _, tc := range tests {
+		h.FlushDB(t, r)
+		h.SeedTasks(t, r, fixtures.tasks)
+		h.SeedRedisSets(t, r, fixtures.allGroups)
+		h.SeedRedisZSets(t, r, fixtures.groups)
+
+		t.Run(tc.desc, func(t *testing.T) {
+			got, err := inspector.Groups(tc.qname)
+			if err != nil {
+				t.Fatalf("Groups returned error: %v", err)
+			}
+			if diff := cmp.Diff(tc.want, got, sortGroupInfosOpt); diff != "" {
+				t.Errorf("Groups = %v, want %v; (-want,+got)\n%s", got, tc.want, diff)
+			}
+		})
+	}
+}
diff --git a/internal/rdb/inspect_test.go b/internal/rdb/inspect_test.go
index 0da4915..ae3c608 100644
--- a/internal/rdb/inspect_test.go
+++ b/internal/rdb/inspect_test.go
@@ -513,7 +513,6 @@ func TestGroupStats(t *testing.T) {
 			}
 		})
 	}
-
 }
 
 func TestGetTaskInfo(t *testing.T) {