diff --git a/fs.go b/fs.go
index 042d3d7..77cf25f 100644
--- a/fs.go
+++ b/fs.go
@@ -21,6 +21,7 @@ var (
 // * Get a temporal file.
 // * Rename files.
 // * Remove files.
+// * Create directories.
 // * Join parts of path.
 // * Obtain a filesystem starting on a subdirectory in the current filesystem.
 // * Get the base path for the filesystem.
@@ -35,6 +36,7 @@ type Filesystem interface {
 	TempFile(dir, prefix string) (File, error)
 	Rename(from, to string) error
 	Remove(filename string) error
+	MkdirAll(filename string, perm os.FileMode) error
 	Join(elem ...string) string
 	Dir(path string) Filesystem
 	Base() string
diff --git a/memfs/memory.go b/memfs/memory.go
index dcafd71..08b701b 100644
--- a/memfs/memory.go
+++ b/memfs/memory.go
@@ -46,15 +46,19 @@ func (fs *Memory) OpenFile(filename string, flag int, perm os.FileMode) (billy.F
 	fullpath := fs.Join(fs.base, filename)
 	f, ok := fs.s.files[fullpath]
 
-	if !ok && !isCreate(flag) {
-		return nil, os.ErrNotExist
-	}
+	if !ok {
+		if !isCreate(flag) {
+			return nil, os.ErrNotExist
+		}
 
-	if f == nil {
 		fs.s.files[fullpath] = newFile(fs.base, fullpath, flag)
 		return fs.s.files[fullpath], nil
 	}
 
+	if f.isDir {
+		return nil, fmt.Errorf("cannot open directory: %s", filename)
+	}
+
 	n := newFile(fs.base, fullpath, flag)
 	n.content = f.content
 
@@ -73,12 +77,13 @@ func (fs *Memory) OpenFile(filename string, flag int, perm os.FileMode) (billy.F
 func (fs *Memory) Stat(filename string) (billy.FileInfo, error) {
 	fullpath := fs.Join(fs.base, filename)
 
-	if _, ok := fs.s.files[fullpath]; ok {
+	f, ok := fs.s.files[fullpath]
+	if ok && !f.isDir {
 		return newFileInfo(fs.base, fullpath, fs.s.files[fullpath].content.Len()), nil
 	}
 
 	info, err := fs.ReadDir(fullpath)
-	if err == nil && len(info) != 0 {
+	if err == nil && len(info) != 0 || f != nil && f.isDir {
 		fi := newFileInfo(fs.base, fullpath, len(info))
 		fi.isDir = true
 		return fi, nil
@@ -101,6 +106,10 @@ func (fs *Memory) ReadDir(base string) (entries []billy.FileInfo, err error) {
 		parts := strings.Split(fullpath, string(separator))
 
 		if len(parts) == 1 {
+			if f.isDir {
+				entries = append(entries, &fileInfo{name: parts[0], isDir: true})
+			}
+
 			entries = append(entries, &fileInfo{name: parts[0], size: f.content.Len()})
 			continue
 		}
@@ -116,6 +125,22 @@ func (fs *Memory) ReadDir(base string) (entries []billy.FileInfo, err error) {
 	return
 }
 
+// MkdirAll creates a directory.
+func (fs *Memory) MkdirAll(path string, perm os.FileMode) error {
+	fullpath := fs.Join(fs.base, path)
+	f, ok := fs.s.files[fullpath]
+	if ok {
+		if !f.isDir {
+			return fmt.Errorf("%s is a file", path)
+		}
+
+		return nil
+	}
+
+	fs.s.files[fullpath] = &file{isDir: true}
+	return nil
+}
+
 var maxTempFiles = 1024 * 4
 
 // TempFile creates a new temporary file.
@@ -207,6 +232,7 @@ type file struct {
 	content  *content
 	position int64
 	flag     int
+	isDir    bool
 }
 
 func newFile(base, fullpath string, flag int) *file {
diff --git a/osfs/os.go b/osfs/os.go
index 55bd638..71e9cd7 100644
--- a/osfs/os.go
+++ b/osfs/os.go
@@ -10,6 +10,11 @@ import (
 	"srcd.works/go-billy.v1"
 )
 
+const (
+	defaultDirectoryMode = 0755
+	defaultCreateMode    = 0666
+)
+
 // OS is a filesystem based on the os filesystem
 type OS struct {
 	base string
@@ -25,7 +30,7 @@ func New(baseDir string) *OS {
 // Create creates a file and opens it with standard permissions
 // and modes O_RDWR, O_CREATE and O_TRUNC.
 func (fs *OS) Create(filename string) (billy.File, error) {
-	return fs.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
+	return fs.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_TRUNC, defaultCreateMode)
 }
 
 // OpenFile is equivalent to standard os.OpenFile.
@@ -55,7 +60,7 @@ func (fs *OS) OpenFile(filename string, flag int, perm os.FileMode) (billy.File,
 func (fs *OS) createDir(fullpath string) error {
 	dir := filepath.Dir(fullpath)
 	if dir != "." {
-		if err := os.MkdirAll(dir, 0755); err != nil {
+		if err := os.MkdirAll(dir, defaultDirectoryMode); err != nil {
 			return err
 		}
 	}
@@ -93,6 +98,12 @@ func (fs *OS) Rename(from, to string) error {
 	return os.Rename(from, to)
 }
 
+// MkdirAll creates a directory.
+func (fs *OS) MkdirAll(path string, perm os.FileMode) error {
+	fullpath := fs.Join(fs.base, path)
+	return os.MkdirAll(fullpath, defaultDirectoryMode)
+}
+
 // Open opens a file in read-only mode.
 func (fs *OS) Open(filename string) (billy.File, error) {
 	return fs.OpenFile(filename, os.O_RDONLY, 0)
diff --git a/test/fs_suite.go b/test/fs_suite.go
index d799ba7..e0b4a88 100644
--- a/test/fs_suite.go
+++ b/test/fs_suite.go
@@ -516,6 +516,14 @@ func (s *FilesystemSuite) TestRemoveAllNonExistent(c *C) {
 	c.Assert(RemoveAll(s.Fs, "non-existent"), IsNil)
 }
 
+func (s *FilesystemSuite) TestRemoveAllEmptyDir(c *C) {
+	c.Assert(s.Fs.MkdirAll("empty", os.FileMode(0755)), IsNil)
+	c.Assert(RemoveAll(s.Fs, "empty"), IsNil)
+	_, err := s.Fs.Stat("empty")
+	c.Assert(err, NotNil)
+	c.Assert(os.IsNotExist(err), Equals, true)
+}
+
 func (s *FilesystemSuite) TestRemoveAll(c *C) {
 	fnames := []string{
 		"foo/1",
@@ -569,3 +577,60 @@ func (s *FilesystemSuite) TestRemoveAllRelative(c *C) {
 		c.Assert(os.IsNotExist(err), Equals, true, comment)
 	}
 }
+
+func (s *FilesystemSuite) TestMkdirAll(c *C) {
+	err := s.Fs.MkdirAll("empty", os.FileMode(0755))
+	c.Assert(err, IsNil)
+	fi, err := s.Fs.Stat("empty")
+	c.Assert(err, IsNil)
+	c.Assert(fi.IsDir(), Equals, true)
+}
+
+func (s *FilesystemSuite) TestMkdirAllNested(c *C) {
+	err := s.Fs.MkdirAll("foo/bar/baz", os.FileMode(0755))
+	c.Assert(err, IsNil)
+	fi, err := s.Fs.Stat("foo/bar/baz")
+	c.Assert(err, IsNil)
+	c.Assert(fi.IsDir(), Equals, true)
+}
+
+func (s *FilesystemSuite) TestMkdirAllIdempotent(c *C) {
+	err := s.Fs.MkdirAll("empty", os.FileMode(0755))
+	c.Assert(err, IsNil)
+	fi, err := s.Fs.Stat("empty")
+	c.Assert(err, IsNil)
+	c.Assert(fi.IsDir(), Equals, true)
+
+	// idempotent
+	err = s.Fs.MkdirAll("empty", os.FileMode(0755))
+	c.Assert(err, IsNil)
+	fi, err = s.Fs.Stat("empty")
+	c.Assert(err, IsNil)
+	c.Assert(fi.IsDir(), Equals, true)
+}
+
+func (s *FilesystemSuite) TestMkdirAllAndOpenFile(c *C) {
+	err := s.Fs.MkdirAll("dir", os.FileMode(0755))
+	c.Assert(err, IsNil)
+
+	f, err := s.Fs.Create("dir/bar/foo")
+	c.Assert(err, IsNil)
+	c.Assert(f.Close(), IsNil)
+
+	fi, err := s.Fs.Stat("dir/bar/foo")
+	c.Assert(err, IsNil)
+	c.Assert(fi.IsDir(), Equals, false)
+}
+
+func (s *FilesystemSuite) TestMkdirAllWithExistingFile(c *C) {
+	f, err := s.Fs.Create("dir/foo")
+	c.Assert(err, IsNil)
+	c.Assert(f.Close(), IsNil)
+
+	err = s.Fs.MkdirAll("dir/foo", os.FileMode(0755))
+	c.Assert(err, NotNil)
+
+	fi, err := s.Fs.Stat("dir/foo")
+	c.Assert(err, IsNil)
+	c.Assert(fi.IsDir(), Equals, false)
+}