Doctor startled by scooter in hospital (as Dr. Praful Kulkarni)
Jalil Parkar
Doctor1 Attending on Raju's Father (as Dr. Jalil Parkar)
Debashish Naha
Doctor2 Attending on Raju's Father (as Dr. Debashish Naha)
Michael Joseph
Exam Hall Professor
Smriti
Girl at Notice Board with Chatur
Sanjay Sood
Peanut Vendor at Shimla
Dayal Sharma
Caretaker at Shyamaldas' House
Rakesh Sharma
Minister at Shyamaldas' Funeral
Elihud George
Chote's Teacher (Masterji)
Sarvanna
College Security Guard
Tanveer Ahmed
Professor in Induction Motor Class
Shankar Sachdev
Ambulance Driver
Kishor Patil
Doctor in Ambulance with Raju (as Dr. Kishor Patil)
Insia Lacewalla
Nurse
Keshav Rae
Campus Interview Panelist 1
Lata Kurdikar
Campus Interview Panelist 2 (as Mrs Lata Kurdikar)
Suhas Vaidya
Campus Interview Panelist 3
Nishi Singh
Maid at Pia's House
Saurabh Agnihotri
Housekeeping Boy at Pia's Wedding
Sitaram Sharma
Manager at Pia's Wedding
Pundit Prayag Raj
Panditji at Pia's Wedding
Supriya Shukla
Matron in Hospital with Pia
Malvika Singh
Mona's Baby
Tsanwal Namgyal
Kid 1 at Rancho's School
Jigmet Dorjey
Kid 2 at Rancho's School
Pitobash
Junior 1
Bharat Jha
Manager (uncredited)
Did you know?
Trivia
Aamir Khan got inspired by A.R.Murugadoss (who directed him in Ghajini earlier) for the dressing sense and body language of the lead character 'Rancho'.
Producer Vidhu Vinod Chopra has claimed that 3 Idiots will be legally released on YouTube within 12 weeks of releasing in theaters - a first in the history of Indian cinema.
When the librarian Mr. Dubey narrates the speech to Chatur, he begins with this line: "Hamare director Sahab Ne Yahaan Kai Chamatkar Kiye Hain!" In the actual speech this line is missing! And Rancho did not change the speech; he only changed some words and added a Sanskrit Shlok.
One of the first scenes, with Madhavan in an Air India aircraft, shows a distant shot of the aircraft to be an Airbus 321. Though, when moments later when the captain calls for an emergency landing at Delhi, the cockpit is that of a Boeing.
During the baby delivery scenes, supposedly taking place around 2003, both parties engaged in the video chat use Google Chrome web browser which was not released until 2008.
About 20% of the plot and characters of 3 Idiots was inspired from Indian writer Chetan Bhagat's "Five Point Someone". Despite there was no such thing taken from the book, the writer was given a special thanks when the credit rolls in the end.