diff --git a/cmd/thanos/compact.go b/cmd/thanos/compact.go
index dd462d6b51..221901f7e5 100644
--- a/cmd/thanos/compact.go
+++ b/cmd/thanos/compact.go
@@ -95,6 +95,9 @@ func registerCompact(m map[string]setupFunc, app *kingpin.Application, name stri
 	blockSyncConcurrency := cmd.Flag("block-sync-concurrency", "Number of goroutines to use when syncing block metadata from object storage.").
 		Default("20").Int()
 
+	groupCompactConcurrency := cmd.Flag("group-compact-concurrency", "Number of goroutines to use when compacting group.").
+		Default("1").Int()
+
 	m[name] = func(g *run.Group, logger log.Logger, reg *prometheus.Registry, tracer opentracing.Tracer, _ bool) error {
 		return runCompact(g, logger, reg,
 			*httpAddr,
@@ -112,6 +115,7 @@ func registerCompact(m map[string]setupFunc, app *kingpin.Application, name stri
 			*disableDownsampling,
 			*maxCompactionLevel,
 			*blockSyncConcurrency,
+			*groupCompactConcurrency,
 		)
 	}
 }
@@ -131,6 +135,7 @@ func runCompact(
 	disableDownsampling bool,
 	maxCompactionLevel int,
 	blockSyncConcurrency int,
+	groupCompactConcurrency int,
 ) error {
 	halted := prometheus.NewGauge(prometheus.GaugeOpts{
 		Name: "thanos_compactor_halted",
@@ -206,7 +211,7 @@ func runCompact(
 
 	ctx, cancel := context.WithCancel(context.Background())
 	f := func() error {
-		if err := compactor.Compact(ctx); err != nil {
+		if err := compactor.Compact(ctx, groupCompactConcurrency); err != nil {
 			return errors.Wrap(err, "compaction failed")
 		}
 		level.Info(logger).Log("msg", "compaction iterations done")
diff --git a/docs/components/compact.md b/docs/components/compact.md
index 2eb6a99824..668c121d08 100644
--- a/docs/components/compact.md
+++ b/docs/components/compact.md
@@ -70,5 +70,7 @@ Flags:
       --block-sync-concurrency=20  
                            Number of goroutines to use when syncing block
                            metadata from object storage.
+      --group-compact-concurrency=1  
+                           Number of goroutines to use when compacting group.
 
 ```
diff --git a/pkg/compact/compact.go b/pkg/compact/compact.go
index ca05adfb4a..0ed9582b37 100644
--- a/pkg/compact/compact.go
+++ b/pkg/compact/compact.go
@@ -886,7 +886,7 @@ func NewBucketCompactor(logger log.Logger, sy *Syncer, comp tsdb.Compactor, comp
 }
 
 // Compact runs compaction over bucket.
-func (c *BucketCompactor) Compact(ctx context.Context) error {
+func (c *BucketCompactor) Compact(ctx context.Context, groupCompactConcurrency int) error {
 	// Loop over bucket and compact until there's no work left.
 	for {
 		// Clean up the compaction temporary directory at the beginning of every compaction loop.
@@ -913,22 +913,42 @@ func (c *BucketCompactor) Compact(ctx context.Context) error {
 			return errors.Wrap(err, "build compaction groups")
 		}
 		finishedAllGroups := true
+		var wg sync.WaitGroup
+		errChan := make(chan error, len(groups))
+		groupChan := make(chan struct{}, groupCompactConcurrency)
+		defer close(groupChan)
+		for i := 0; i < groupCompactConcurrency; i++ {
+			groupChan <- struct{}{}
+		}
 		for _, g := range groups {
-			shouldRerunGroup, _, err := g.Compact(ctx, c.compactDir, c.comp)
-			if err == nil {
-				if shouldRerunGroup {
-					finishedAllGroups = false
+			<-groupChan
+			wg.Add(1)
+			go func(g *Group) {
+				defer func() {
+					wg.Done()
+					groupChan <- struct{}{}
+				}()
+				shouldRerunGroup, _, err := g.Compact(ctx, c.compactDir, c.comp)
+				if err == nil {
+					if shouldRerunGroup {
+						finishedAllGroups = false
+					}
+					return
 				}
-				continue
-			}
 
-			if IsIssue347Error(err) {
-				if err := RepairIssue347(ctx, c.logger, c.bkt, err); err == nil {
-					finishedAllGroups = false
-					continue
+				if IsIssue347Error(err) {
+					if err := RepairIssue347(ctx, c.logger, c.bkt, err); err == nil {
+						finishedAllGroups = false
+						return
+					}
 				}
-			}
-			return errors.Wrap(err, "compaction")
+				errChan <- errors.Wrap(err, "compaction")
+			}(g)
+		}
+		wg.Wait()
+		close(errChan)
+		if err := <-errChan; err != nil {
+			return err
 		}
 		if finishedAllGroups {
 			break