diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 5dc055fc0..8b495d6ee 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -250,7 +250,10 @@ class ManyPrimaryKeyRelatedField(PrimaryKeyRelatedField):
             value = data.getlist(field_name)
         except:
             value = data.get(field_name)
-        into[field_name] = [self.from_native(item) for item in value if item]
+        else:
+            if value == ['']:
+                value = []
+        into[field_name] = [self.from_native(item) for item in value]
 
 
 class NaturalKeyRelatedField(RelatedField):