Index: twisted/test/test_ftp.py
===================================================================
--- twisted/test/test_ftp.py	(revision 34577)
+++ twisted/test/test_ftp.py	(working copy)
@@ -2588,7 +2588,53 @@
         d = self.shell.access(('foo',))
         return self.assertFailure(d, ftp.FileNotFoundError)
 
+    def test_accessNotAllowed(self):
+        """
+        access should fail on a resource for which we can't list its content.
+        """
+        path = 'foo'
+        self.createDirectory(path)
+        self.root.child(path).chmod(0000)
+        d = self.shell.access((path,))
 
+        def revert_permissions(result_or_failure):
+            """Folder permissions are reverted so that any clean function
+            will be allowed to remove the folder.
+            """
+            self.root.child(path).chmod(0700)
+            self.root.child(path).remove()
+            return result_or_failure
+
+        d.addBoth(revert_permissions)
+        return self.assertFailure(d, ftp.PermissionDeniedError)
+
+    if not os.name == 'posix':
+        test_accessNotAllowed.skip = "test_accessNotAllowed not supported"
+
+    def test_accessNoExecutePermissions(self):
+        """
+        access should fail on a resource for which we can't list its content.
+        """
+        path = 'foo'
+        self.createDirectory(path)
+        self.root.child(path).chmod(0600)
+        d = self.shell.access((path,))
+
+        def revert_permissions(result_or_failure):
+            """Folder permissions are reverted so that any cleanup will be
+            allowed to remove the folder.
+            """
+            self.root.child(path).chmod(0700)
+            self.root.child(path).remove()
+            return result_or_failure
+
+        d.addBoth(revert_permissions)
+        return self.assertFailure(d, ftp.PermissionDeniedError)
+
+    if not os.name == 'posix':
+        test_accessNoExecutePermissions.skip = (
+            "test_accessNoExecutePermissions not supported")
+
     def test_openForReading(self):
         """
         Check that openForReading returns an object providing C{ftp.IReadFile}.
Index: twisted/protocols/ftp.py
===================================================================
--- twisted/protocols/ftp.py	(revision 34577)
+++ twisted/protocols/ftp.py	(working copy)
@@ -1672,24 +1672,52 @@
         """
         return defer.fail(PermissionDeniedError("STOR not allowed"))
 
+    def access(self, path):
+        """
+        See L{IFTPShell.access}.
 
-    def access(self, path):
+        If path doesn't exists, it returns L{FileNotFoundError}.
+        On Unix systems, it checks path access by trying to change current
+        working directory.
+        On non-Unix systems, it checks path access by issuing a folder
+        listing command.
+        """
         p = self._path(path)
         if not p.exists():
             # Again, win32 doesn't report a sane error after, so let's fail
-            # early if we can
+            # early if we can.
             return defer.fail(FileNotFoundError(path))
-        # For now, just see if we can os.listdir() it
-        try:
-            p.listdir()
-        except (IOError, OSError), e:
-            return errnoToFailure(e.errno, path)
-        except:
-            return defer.fail()
-        else:
+
+        def check_access_chdir():
+            '''Check access by changing working folder.'''
+            current_path = os.getcwd()
+            try:
+                os.chdir(p.path)
+            except (IOError, OSError), e:
+                return errnoToFailure(e.errno, path)
+            except:
+                return defer.fail()
+            finally:
+                os.chdir(current_path)
+
             return defer.succeed(None)
 
+        def check_access_listdir():
+            '''Check access by listing folder.'''
+            try:
+                os.listdir(p.path)
+            except (IOError, OSError), e:
+                return errnoToFailure(e.errno, path)
+            except:
+                return defer.fail()
 
+            return defer.succeed(None)
+
+        if os.name == 'posix':
+            return check_access_chdir()
+        else:
+            return check_access_listdir()
+
     def stat(self, path, keys=()):
         p = self._path(path)
         if p.isdir():