In Hindi films, he played the comedian's role from 1966 to 2013 and played supporting actor's role as the close friend of the lead hero in many films between 1972-1994. In a few Hindi films like Chala Murari Hero Banne and Salaam Memsaab he played the main lead hero. In Gujarati films he played the lead hero from 1972 to 1984 and played character roles from 1985 to 2012. He has also directed 6 films between 1974-1997.
Asrani was born in a middle class Hindu Sindhi family. His father migrated to Jaipur after the Partition of India and opened a shop selling carpets. He has four sisters and three brothers: two elder and one younger. Asrani was highly uninterested in business and very weak in mathematics. He completed his matriculation from St. Xaviers School and did his graduation from Rajasthan College, Jaipur. He simultaneously worked as a voice artist at All India Radio, Jaipur, to pay for his education. His ultimate aim was to become an actor.
He is married to actress Manju (née Bansal), with whom he fell in love working together in films like Aaj Ki Taaza Khabar and Namak Haram. Later after marriage the couple acted in Tapasya, Chandi Sona, Jaan-E-Bahaar, Jurmana, Nalayak, Sarkari Mehmaan and Chor Sipahee. In Aaj Ki Taza Khabar, Asrani played as Champak Boomia / Amit Desai and Manju played role of Kesari Desai and for this role Asrani won Filmfare Award for Best Comedian. Later the couple acted in Hum Nahin Sudhrenge, a home production directed by Asrani in 1980. His son Naveen Asrani is a dentist in Ahmedabad.
He began to learn acting from Sahitya Kalbhai Thakkar from 1960 to 1962. In 1962, he travelled to Bombay (now Mumbai) and began to seek opportunities to act. In 1963, on an accidental meeting with Kishore Sahu and Hrishikesh Mukherjee, they advised him to learn acting professionally.
In 1964 Asrani joined the Film Institute in Poona (now Film and Television Institute of India, Pune) and finished his course in 1966. He got his first break in Hindi films playing the friend of actor Biswajeet in the film Hare Kaanch Ki Choodiyan in 1967. In the film institute he had impressed many and made his acting break as a hero in 1967 with a Gujarati movie opposite budding actress Waheeda (not Waheeda Rahman; the Hindi actress). He acted in four other movies, mainly as actor or supporting actor in Gujarati from 1967 to 1969. He did not get much offers from Hindi film industry between 1967-69. His old advisor, Hrishikesh Mukherjee then gave him role of supporting actor in the film Satyakam in 1969. He got noticed then in the film Mere Apne. It was from 1971 that he started getting more offers as the main comedian in films or as the close friend of the lead actor.
Directors like Hrishikesh Mukherjee, Atma Ram, Gulzar repeatedly cast him in the period 1971-1974 and his work got noticed through these films. These roles he did from 1971-1974 set the tone for a number of supporting and comic roles in his career and in the 1970s his demand was at its peak as he appeared in 101 films from 1970-1979 and had effective roles in them. Though initially Rajesh Khanna and Asrani had met only on sets of Bawarchi, they became close friends after Namak Haraam, after which for the role of comedian Rajesh Khanna insisted the producers and directors to make Asrani part of his films. Asrani worked in 25 films with Rajesh Khanna from 1972-1991 from Bawarchi (1972) to Ghar Parivaar (1991). His most memorable works as supporting actor from 1970-1979 are in Mere Apne, Koshish, Bawarchi, Parichay, Abhimaan, Mehbooba, Palkon Ki Chhaon Mein, Do Ladke Dono Kadke and Bandish. He played the lead hero in Chala Murari Hero Banne, a Hindi film he wrote and directed in 1977, which was critically acclaimed. His notable role as comedian from the 1970s are in Aaj Ki Taaza Khabar, Roti, Prem Nagar, Chupke Chupke, Chhoti Si Baat, Rafoo Chakkar, Sholay, Balika Badhu, Fakira, Anurodh, Chhailla Babu, Charas, Phaansi, Dillagi, Heeralal Pannalal, Pati Patni Aur Woh and Hamare Tumhare. Though he had played supporting character in many films even before, he played a serious role for first time in Khoon Pasina. He was hugely talked about in the 1970s and was one of Rajesh Khanna's close friends. He became a regular feature in films produced by D. Rama Naidu and those movies directed by Hrishikesh Mukherjee, B.R.Chopra, K. Bapaiah, Narayana Rao Dasari, K. Raghavendra Rao, Basu Chatterjee in 1972-1992. He won the Filmfare award for Best Comedian for his performances in Aaj Ki Taaza Khabar in 1974 and for Balika Badhu in 1977. In 1974, he directed his first movie in Gujarati with Asrani himself as the hero, and the song "Hu Amdavad No Rikshawalo" sung by Kishore Kumar was picturised on Asrani. The songs picturised on Asrani and sung by Kishore in Hindi are "Achcha Chaloji Baba Maaf Kardo" from Hamare Tumhare, "Pyar Main Karoonga" from Yeh Kaisa Insaaf. The song "Mannu Bhai Motor Chali Pam" was sung by him with Kishore Kumar and was picturised on Rishi Kapoor and him, in Phool Khile Hain Gulshan Gulshan in 1978.
In the 1980s, he acted in 107 Hindi films. Asrani holds record for appearing as a character actor/comedian in most number of Hindi films in a decade – 101 in the 1970s and 107 in the 1980s. Unlike his roles in 1970-84 which were pivotal to the plot, most of his roles from 1985-1993 were very minor mainly because the concept of a comedian was getting phased out and heroes preferred to do their own comedy and action films were ruling the roost in the period 1985-1994. In the 1980s his memorable performances were in Hamari Bahu Alka, Ek Hi Bhool, Yeh Kaisa Insaf, Kaamchor, Agar Tum Na Hote, Asha Jyoti, Maqsad, Main Intequam Loonga, Love 86 and Biwi Ho To Aisi. During this period in 1982, he set up a small Gujarati production company with fellow artistes Dinesh Hingoo, Harish Patel and Salim Parvez (son of famous supporting actor Yunus Parvez). The company dissolved in 1996 with a large profit. Asrani also invested mainly in cloth and acted as investor for other actors, until 1991 when he lost a lot of money. From 1988 to 1993, he was a director for the Film Institute in Pune. It was only from 1985-1994 that his screen space in the Hindi films was for less duration. In the 1990s he did only 73 Hindi movies due to lack of good scope for him to perform. Muqabla (1993) saw him in a serious role after long time.
Simultaneously he kept working in Gujarati films in the 1970s and 1980s as a lead hero and achieved success as the lead protagonist in Amdavad No Rikshawalo, Saat Qaidi, Sansar Chakra, Pankhi No Malo, Jugal Jodi, Maa Baap, Chel Chabilo Gujarati. From the 1990s he played as comedian or supporting actor in Gujarati films like Mota Ghar Ni Vahu, Piyu Gayo Pardesh, and Baap Dhamal Dikhra.
D.Rama Naidu gave a pivotal role to Asrani in Taqdeerwala in 1995 and once again comedy movies were being made from there on . Asrani started getting good roles in films directed by David Dhawan and Priyadarshan from 1993 until 2012. His most memorable performances as comedian from the 1990s are in Jo Jeeta Wohi Sikandar, Gardish, Taqdeerwala, Gharwali Baharwali, Bade Miyan Chote Miyan and Hero Hindustani.
The 2000s saw Asrani in a number of films like Hera Pheri, Chup Chup Ke, Hulchul, Deewane Huye Paagal, Garam Masala, Chup Chup Ke, Malamaal Weekly, Bhagam Bhag, De Dana Dan, Bol Bachchan, Kamaal Dhamaal Malamaal which had him in effective comedy roles. He appeared in a serious role in Kyun Ki. He was an integral part of comedies by Sajid Nadiadwala, Priyadarshan after 2000. His screen space in films of Rohit Shetty and others has got reduced gradually after 2009.
Asrani and Mallika Sherawat were the judges of the 18th annual Naya Andaz competition on 17 April 2010, in New Jersey.
Asrani is now playing the role of Mikesh's grandfather in the popular web series Permanent Roommates.
Asrani also won the Best Actor, Best Director Award from Gujarat State Government for Saat Qaidi, a Gujarati language film.