diff --git a/docs/changelog.rst b/docs/changelog.rst
index f0adcbe5..58859a58 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -5,6 +5,7 @@ Changelog
 Changes in 0.6.X
 ================
 
+- Fixed BinaryField python value issue (MongoEngine/mongoengine#48)
 - Fixed queryset manager issue (MongoEngine/mongoengine#52)
 - Fixed FileField comparision (hmarr/mongoengine#547)
 
diff --git a/mongoengine/fields.py b/mongoengine/fields.py
index 89b81cdb..27434e67 100644
--- a/mongoengine/fields.py
+++ b/mongoengine/fields.py
@@ -845,12 +845,9 @@ class BinaryField(BaseField):
     def to_mongo(self, value):
         return Binary(value)
 
-    def to_python(self, value):
-        return "%s" % value
-
     def validate(self, value):
-        if not isinstance(value, basestring):
-            self.error('BinaryField only accepts string values')
+        if not isinstance(value, (basestring, Binary)):
+            self.error('BinaryField only accepts string or bson Binary values')
 
         if self.max_bytes is not None and len(value) > self.max_bytes:
             self.error('Binary value is too long')
diff --git a/tests/test_fields.py b/tests/test_fields.py
index 4e708563..29f5fe97 100644
--- a/tests/test_fields.py
+++ b/tests/test_fields.py
@@ -6,6 +6,7 @@ import StringIO
 import tempfile
 import gridfs
 
+from bson import Binary
 from decimal import Decimal
 
 from mongoengine import *
@@ -1428,7 +1429,7 @@ class FieldTest(unittest.TestCase):
 
         attachment_1 = Attachment.objects().first()
         self.assertEqual(MIME_TYPE, attachment_1.content_type)
-        self.assertEqual(BLOB, attachment_1.blob)
+        self.assertEqual(BLOB, str(attachment_1.blob))
 
         Attachment.drop_collection()
 
@@ -1455,7 +1456,7 @@ class FieldTest(unittest.TestCase):
 
         attachment_required = AttachmentRequired()
         self.assertRaises(ValidationError, attachment_required.validate)
-        attachment_required.blob = '\xe6\x00\xc4\xff\x07'
+        attachment_required.blob = Binary('\xe6\x00\xc4\xff\x07')
         attachment_required.validate()
 
         attachment_size_limit = AttachmentSizeLimit(blob='\xe6\x00\xc4\xff\x07')
@@ -1467,6 +1468,18 @@ class FieldTest(unittest.TestCase):
         AttachmentRequired.drop_collection()
         AttachmentSizeLimit.drop_collection()
 
+    def test_binary_field_primary(self):
+
+        class Attachment(Document):
+            id = BinaryField(primary_key=True)
+
+        Attachment.drop_collection()
+
+        att = Attachment(id=uuid.uuid4().bytes).save()
+        att.delete()
+
+        self.assertEqual(0, Attachment.objects.count())
+
     def test_choices_validation(self):
         """Ensure that value is in a container of allowed values.
         """