diff --git a/swh/model/from_disk.py b/swh/model/from_disk.py
--- a/swh/model/from_disk.py
+++ b/swh/model/from_disk.py
@@ -10,7 +10,7 @@
 
 import attr
 from attrs_strict import type_validator
-from typing import List, Optional, Iterable, Any
+from typing import Any, Iterable, List, Optional, Tuple
 from typing_extensions import Final
 
 from .hashutil import MultiHash
@@ -279,6 +279,42 @@
     return named_filter
 
 
+def iter_directory(
+    directory,
+) -> Tuple[
+    Iterable[model.Content], Iterable[model.SkippedContent], Iterable[model.Directory]
+]:
+    """Return the directory listing from a disk-memory directory instance.
+
+    Raises:
+        TypeError in case an unexpected object type is listed.
+
+    Returns:
+        Tuple of respectively iterable of content, skipped content and directories.
+
+    """
+    contents: List[model.Content] = []
+    skipped_contents: List[model.SkippedContent] = []
+    directories: List[model.Directory] = []
+
+    for obj in directory.iter_tree():
+        obj = obj.to_model()
+        obj_type = obj.object_type
+        if obj_type in ("content", "content_file"):
+            # FIXME: read the data from disk later (when the
+            # storage buffer is flushed).
+            obj = obj.with_data()
+            contents.append(obj)
+        elif obj_type == "skipped_content":
+            skipped_contents.append(obj)
+        elif obj_type == "directory":
+            directories.append(obj)
+        else:
+            raise TypeError(f"Unexpected object type from disk: {obj}")
+
+    return contents, skipped_contents, directories
+
+
 class Directory(MerkleNode):
     """Representation of a Software Heritage directory as a node in a Merkle Tree.
 
diff --git a/swh/model/tests/test_from_disk.py b/swh/model/tests/test_from_disk.py
--- a/swh/model/tests/test_from_disk.py
+++ b/swh/model/tests/test_from_disk.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2017 The Software Heritage developers
+# Copyright (C) 2017-2020 The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -9,6 +9,7 @@
 import tempfile
 import unittest
 
+from collections import defaultdict
 from typing import ClassVar, Optional
 
 from swh.model import from_disk
@@ -858,6 +859,31 @@
                 raise self.failureException("Unknown type for %s" % obj)
 
 
+class TarballIterDirectory(DataMixin, unittest.TestCase):
+    def setUp(self):
+        super().setUp()
+        self.make_from_tarball(self.tmpdir_name)
+
+    def test_iter_directory(self):
+        """Iter from_disk.directory should yield the full arborescence tree
+
+        """
+        directory = Directory.from_disk(
+            path=os.path.join(self.tmpdir_name, b"sample-folder")
+        )
+
+        contents, skipped_contents, directories = from_disk.iter_directory(directory)
+
+        expected_nb = defaultdict(int)
+        for name in self.tarball_contents.keys():
+            obj = directory[name]
+            expected_nb[obj.object_type] += 1
+
+        assert len(contents) == expected_nb["content"] and len(contents) > 0
+        assert len(skipped_contents) == 0
+        assert len(directories) == expected_nb["directory"] and len(directories) > 0
+
+
 class DirectoryManipulation(DataMixin, unittest.TestCase):
     def test_directory_access_nested(self):
         d = Directory()