The 12th IIFA Award 2011 winners list , the categories will be as given under..
Also for more Updates on 12th IIFA Awards 2011 check this link – 12th IIFA Awards 2011

Here is the list of the winners of the 12th IIFA Awards 2011 Winners
Best Actor – Shahrukh Khan for My Name is Khan
Best Actress – Anushka Sharma for Band Baaja Baaraat


Best Newcomer (Male) - Ranveer Singh
Best Newcomer (Female) – Sonakshi Sinha


Best Supporting Actor – Arjun Rampal for Rajneeti
Best Supporting Actress - Prachi Desai for Once upon a time in Mumbai
Best Comic Role – Riteish Deshmukh

Best Negative Role – Sonu Sood  
Best Director – Karan Johar for My Name is Khan
Best Film – Dabangg


Best Story – Shivani Bhatija for My Name is Khan
Best Lyrics – Niranjan Iyengar for Sajda and Noor – e – Khuda from My Name is Khan
Best Playback Singer Male - Rahat Fateh Ali Khan for Tere Mast Mast Do Nain


Best Playback Singer Female – Mamta Sharma for Munni Badnaam Hui
Best Music Director – Sajid-Wajid / Lalit Pandit


Technical Awards:
Best Costume Designing – Niharika Khan – Band Baaja Baaraat
Best Action – S. Vijayan – Dabangg


Best Makeup – Banu (For Rajnikant) – Robot
Best Background Score – Shankar, Ehsaan, Loy – My Name Is Khan


Best Song Recording – Vijay Dayal and Ainvayi Ainvayi – Band Baaja Baaraat
Best Choreography Award – Farah Khan – Munni Badnam for Dabangg


Best Editing – Namrata Rao – Band Baaja Baaraat
Best Sound Recording – Pritam Das – Love, Sex Aur Dhokha
Best Dialogue -


Best Sound Re-recording – Leslie Fernandes – Dabangg
Best Screenplay –


Best Cinematography – Sudeep Chatterjee – Guzaarish
Best Art Direction – Sabu Cyril – Robot


Best Special Effects -Indian Artists – Robot