Directed by:
- Rajkumar Hirani
- Vidhu Vinod Chopra
- Rajkumar Hirani
- Abhijit Joshi
- Aamir Khan ... Rancho
- Kareena Kapoor ... Pia V. Sahastrabudhhe
- Sharman Joshi ... Raju Rastogi
- Madhavan ... Farhan Qureshi
- Boman Irani ... Viru Sahastrabudhhe
- Omi Vaidya ... Chatur 'Silencer' Ramalingam
- Mona Singh ... Mona
- Javed Jaffrey ... Ranchoddas Shamaldas Chanchad (as Jaaved Jaaferi)
- Ali Fazal ... Joy Lobo
- Rajeev Ravindranathan ... Lead Ragging Senior
- Parikshat Sahni ... Mr. Qureshi (as Parikshit Sahani)
- Akhil Mishra ... Librarian Dubey
- Pitobash ... Junior 1
- Chandrashekhar ... Airlines Ground Staff 2
- Achyut Potdar ... Machine Class Professor
- Rahul Kumar ... Millimetre - MM
- Rakesh Sharma ... Minister at Shyamaldas' Funeral
- Arun Bali ... Shyamaldas Chanchad
- Dushyant Wagh ... Centimetre
- Supriya Shukla ... Matron in Hospital with Pia
- Jayant Kripalani ... Campus Interview Panel Head (as Jayant Kriplani)
- Atul Tiwari ... Minister in Auditorium
- Shoaib Ahmed ... Chhotey
- Amardeep Jha ... Mrs. Rastogi
- Meghna Bhatia ... Mrs. Rastogi
- Malvika Singh ... Mona's Baby
- Dinesh Kumar ... Mona's Husband
- Farida Dadi ... Mrs. Qureshi
- Nishi Singh ... Maid at Pia's House
- Omi ... Chatur - pondicherry boy
- Chaitali Bose ... Kamini 'Kammo' Rastogi
- Hitesh Tak ... Ragging Senior 2
- Pooja Goswami ... Air Hostess
- Michael Joseph ... Exam Hall Professor
- Harvinder Singh ... Mr. Dhillon
- Shankar Sachdev ... Ambulance Driver
- Vaidyanathan ... Professor Vaidyanathan (as Prof. Vaidyanathan)
- Sanjay Sood ... Peanut Vendor at Shimla
- Mukund Bhatt ... Mr. Rastogi
- Shailaja Dhar ... Lady at Mona's Wedding
- Dr. Kishor Patil ... Doctor in Ambulance with Raju
- A.S. Duggal ... Pilot (as Captain A.S. Duggal)
- Apul Jaisinghani ... ICE Student 3
- Saurabh Agnihotri ... Housekeeping Boy at Pia's Wedding
- Rajendra Patwardhan ... Govind
- Dileep Desai ... Priest at Joy's funeral
- Praful Kulkarni ... Doctor startled by scooter in hospital
- Trilok Sadhwani ... ICE Student 4
- Aakash Dabhade ... ICE Student 2
- R.S. Kodange ... Doctor at Airport
- Tanveer Ahmed ... Professor in Induction Motor Class
- Kumar Veer Singh ... Waiter at Mona's Wedding
- Raghunathan ... Professor in Corridor
- Annapurna Kaul ... Airlines Ground Staff 1
- Sarvanna ... College Security Guard
- Pandit Prayag Raj ... Panditji at Pia's Wedding
- Dayal Sharma ... Caretaker at Shyamaldas' House
- Dharmendra Bhurji ... Airport Cab Driver
- Sitaram Sharma ... Manager at Pia's Wedding
- Sonu ... Library Clerk