diff --git a/cmd/restic/cmd_fsck.go b/cmd/restic/cmd_fsck.go
index ae80f0f2a..44e8b307d 100644
--- a/cmd/restic/cmd_fsck.go
+++ b/cmd/restic/cmd_fsck.go
@@ -1,13 +1,24 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/restic/restic"
 	"github.com/restic/restic/backend"
 )
 
-type CmdFsck struct{}
+type CmdFsck struct {
+	CheckData      bool   `          long:"check-data"      description:"Read data blobs" default:"false"`
+	Snapshot       string `short:"s" long:"snapshot"        description:"Only check this snapshot"`
+	Orphaned       bool   `short:"o" long:"orphaned"        description:"Check for orphaned blobs"`
+	RemoveOrphaned bool   `short:"x" long:"remove-orphaned" description:"Remove orphaned blobs (implies -o)"`
+
+	// lists checking for orphaned blobs
+	o_data  *restic.BlobList
+	o_trees *restic.BlobList
+	o_maps  *restic.BlobList
+}
 
 func init() {
 	_, err := parser.AddCommand("fsck",
@@ -19,21 +30,45 @@ func init() {
 	}
 }
 
-func fsckFile(ch *restic.ContentHandler, IDs []backend.ID) error {
+func fsckFile(opts CmdFsck, ch *restic.ContentHandler, IDs []backend.ID) error {
 	for _, id := range IDs {
 		debug("checking data blob %v\n", id)
 
-		// load content
-		_, err := ch.Load(backend.Data, id)
-		if err != nil {
-			return err
+		if opts.CheckData {
+			// load content
+			_, err := ch.Load(backend.Data, id)
+			if err != nil {
+				return err
+			}
+		} else {
+			// test if data blob is there
+			ok, err := ch.Test(backend.Data, id)
+			if err != nil {
+				return err
+			}
+
+			if !ok {
+				return fmt.Errorf("data blob %v not found", id)
+			}
+		}
+
+		// if orphan check is active, record storage id
+		if opts.o_data != nil {
+			// lookup storage ID
+			sid, err := ch.Lookup(id)
+			if err != nil {
+				return err
+			}
+
+			// add ID to list
+			opts.o_data.Insert(restic.Blob{ID: sid})
 		}
 	}
 
 	return nil
 }
 
-func fsckTree(ch *restic.ContentHandler, id backend.ID) error {
+func fsckTree(opts CmdFsck, ch *restic.ContentHandler, id backend.ID) error {
 	debug("checking tree %v\n", id)
 
 	tree, err := restic.LoadTree(ch, id)
@@ -41,6 +76,18 @@ func fsckTree(ch *restic.ContentHandler, id backend.ID) error {
 		return err
 	}
 
+	// if orphan check is active, record storage id
+	if opts.o_trees != nil {
+		// lookup storage ID
+		sid, err := ch.Lookup(id)
+		if err != nil {
+			return err
+		}
+
+		// add ID to list
+		opts.o_trees.Insert(restic.Blob{ID: sid})
+	}
+
 	for i, node := range tree {
 		if node.Name == "" {
 			return fmt.Errorf("node %v of tree %v has no name", i, id)
@@ -56,7 +103,7 @@ func fsckTree(ch *restic.ContentHandler, id backend.ID) error {
 				return fmt.Errorf("file node %q of tree %v has no content", node.Name, id)
 			}
 
-			err := fsckFile(ch, node.Content)
+			err := fsckFile(opts, ch, node.Content)
 			if err != nil {
 				return err
 			}
@@ -65,7 +112,7 @@ func fsckTree(ch *restic.ContentHandler, id backend.ID) error {
 				return fmt.Errorf("dir node %q of tree %v has no subtree", node.Name, id)
 			}
 
-			err := fsckTree(ch, node.Subtree)
+			err := fsckTree(opts, ch, node.Subtree)
 			if err != nil {
 				return err
 			}
@@ -75,7 +122,7 @@ func fsckTree(ch *restic.ContentHandler, id backend.ID) error {
 	return nil
 }
 
-func fsck_snapshot(s restic.Server, id backend.ID) error {
+func fsck_snapshot(opts CmdFsck, s restic.Server, id backend.ID) error {
 	debug("checking snapshot %v\n", id)
 
 	ch, err := restic.NewContentHandler(s)
@@ -96,16 +143,25 @@ func fsck_snapshot(s restic.Server, id backend.ID) error {
 		return fmt.Errorf("snapshot %v has no map", sn.ID)
 	}
 
-	return fsckTree(ch, sn.Tree)
+	// if orphan check is active, record storage id for map
+	if opts.o_maps != nil {
+		opts.o_maps.Insert(restic.Blob{ID: sn.Map})
+	}
+
+	return fsckTree(opts, ch, sn.Tree)
 }
 
 func (cmd CmdFsck) Usage() string {
-	return "fsck [all|snapshot-ID]"
+	return "[fsck-options]"
 }
 
 func (cmd CmdFsck) Execute(args []string) error {
-	if len(args) == 0 {
-		return fmt.Errorf("type or ID not specified, Usage: %s", cmd.Usage())
+	if len(args) != 0 {
+		return errors.New("fsck has no arguments")
+	}
+
+	if cmd.RemoveOrphaned && !cmd.Orphaned {
+		cmd.Orphaned = true
 	}
 
 	s, err := OpenRepo()
@@ -113,27 +169,75 @@ func (cmd CmdFsck) Execute(args []string) error {
 		return err
 	}
 
-	if len(args) == 1 && args[0] != "all" {
-		snapshotID, err := s.FindSnapshot(args[0])
+	if cmd.Snapshot != "" {
+		snapshotID, err := s.FindSnapshot(cmd.Snapshot)
 		if err != nil {
-			return fmt.Errorf("invalid id %q: %v", args[0], err)
+			return fmt.Errorf("invalid id %q: %v", cmd.Snapshot, err)
 		}
 
-		return fsck_snapshot(s, snapshotID)
+		return fsck_snapshot(cmd, s, snapshotID)
+	}
+
+	if cmd.Orphaned {
+		cmd.o_data = restic.NewBlobList()
+		cmd.o_trees = restic.NewBlobList()
+		cmd.o_maps = restic.NewBlobList()
 	}
 
 	list, err := s.List(backend.Snapshot)
+	debug("checking %d snapshots\n", len(list))
 	if err != nil {
 		return err
 	}
 
 	for _, snapshotID := range list {
-		err := fsck_snapshot(s, snapshotID)
+		err := fsck_snapshot(cmd, s, snapshotID)
 
 		if err != nil {
 			return err
 		}
 	}
 
+	if !cmd.Orphaned {
+		return nil
+	}
+
+	debug("starting orphaned check\n")
+
+	l := []struct {
+		desc string
+		tpe  backend.Type
+		list *restic.BlobList
+	}{
+		{"data blob", backend.Data, cmd.o_data},
+		{"tree", backend.Tree, cmd.o_trees},
+		{"maps", backend.Map, cmd.o_maps},
+	}
+
+	for _, d := range l {
+		debug("checking for orphaned %v\n", d.desc)
+
+		blobs, err := s.List(d.tpe)
+		if err != nil {
+			return err
+		}
+
+		for _, id := range blobs {
+			_, err := d.list.Find(restic.Blob{ID: id})
+			if err == restic.ErrBlobNotFound {
+				if !cmd.RemoveOrphaned {
+					fmt.Printf("orphaned %v %v\n", d.desc, id)
+					continue
+				}
+
+				fmt.Printf("removing orphaned %v %v\n", d.desc, id)
+				err := s.Remove(d.tpe, id)
+				if err != nil {
+					return err
+				}
+			}
+		}
+	}
+
 	return nil
 }
diff --git a/cmd/restic/cmd_ls.go b/cmd/restic/cmd_ls.go
index 94d2b04bb..a34f6664f 100644
--- a/cmd/restic/cmd_ls.go
+++ b/cmd/restic/cmd_ls.go
@@ -60,7 +60,7 @@ func print_tree(prefix string, ch *restic.ContentHandler, id backend.ID) error {
 }
 
 func (cmd CmdLs) Usage() string {
-	return "ls snapshot-ID [DIR]"
+	return "snapshot-ID [DIR]"
 }
 
 func (cmd CmdLs) Execute(s restic.Server, key *restic.Key, args []string) error {
diff --git a/cmd/restic/main.go b/cmd/restic/main.go
index 5fec20030..f5c39f5e3 100644
--- a/cmd/restic/main.go
+++ b/cmd/restic/main.go
@@ -130,6 +130,10 @@ func create(u string) (backend.Backend, error) {
 }
 
 func OpenRepo() (restic.Server, error) {
+	if opts.Repo == "" {
+		return restic.Server{}, errors.New("Please specify repository location (-r)")
+	}
+
 	be, err := open(opts.Repo)
 	if err != nil {
 		return restic.Server{}, err
diff --git a/contenthandler.go b/contenthandler.go
index 16fd7a2ab..cba3dc833 100644
--- a/contenthandler.go
+++ b/contenthandler.go
@@ -181,6 +181,17 @@ func (ch *ContentHandler) Load(t backend.Type, id backend.ID) ([]byte, error) {
 	return buf, nil
 }
 
+// Lookup returns the storage ID for the given blob
+func (ch *ContentHandler) Lookup(id backend.ID) (backend.ID, error) {
+	// lookup storage hash
+	blob, err := ch.bl.Find(Blob{ID: id})
+	if err != nil {
+		return nil, err
+	}
+
+	return blob.Storage, nil
+}
+
 // LoadJSON calls Load() to get content from the backend and afterwards calls
 // json.Unmarshal on the item.
 func (ch *ContentHandler) LoadJSON(t backend.Type, id backend.ID, item interface{}) error {
@@ -214,3 +225,21 @@ func (ch *ContentHandler) LoadJSONRaw(t backend.Type, id backend.ID, item interf
 	err = json.Unmarshal(backend.Uncompress(buf), item)
 	return err
 }
+
+// Test checks if a blob is in the repository. For Data and Tree blobs, the
+// storage ID is looked up.
+func (ch *ContentHandler) Test(t backend.Type, id backend.ID) (bool, error) {
+	if t == backend.Data || t == backend.Tree {
+		// lookup storage id
+
+		// lookup storage hash
+		blob, err := ch.bl.Find(Blob{ID: id})
+		if err != nil {
+			return false, fmt.Errorf("Storage ID %s not found", id)
+		}
+
+		id = blob.Storage
+	}
+
+	return ch.s.Test(t, id)
+}