Both Inflectional and derivational morphology lead to multiple surface forms of a word. Stemming reduces these forms back to its stem or root, and is a very useful tool for many applications. There has not been any work reported on Urdu stemming. The current work develops an Urdu stemmer or Assas-Band and improves the performance using more precise affix based exception lists, instead of the conventional lexical lookup employed for developing stemmers in other languages. Testing shows an accuracy of 91.2%. Further enhancements are also suggested.