The actor made his acting debut on the silver screen with the critically acclaimed film, Maachis directed by Gulzar and co-starring, Chandrachur Singh, Jimmy Shergill, Raj Zutshi, Tabu and Om Puri. The film based on the aftermath of the assassination of the Prime Minister of India, Indira Gandhi and the subsequent Anti-Sikh riots in 1984 was a huge commercial hit and won the National Film Award for Best Popular Film Providing Wholesome Entertainment. Following his debut movie, the actor took a sabbatical for four years and made his comeback in 2000 with a Bengali film titled Paromitar Ek Din, written and directed by Aparna Sen. The film starring, Rituparna Sengupta, Aparna Sen, and Soumitra Chatterjee won several national and international awards including the National Film Award for Best Feature Film in Bengali, Ecumenical Jury Award the 35th International Film Festival of Karlovy Vary.
In 2002, the actor appeared in four Bengali films, viz. Sathi, Desh, Shubho Mahurat, and Sonar Sansar. While Sathi and Sonar Sansar did not garner any attention, Sathi directed by Haranath Chakraborty received mixed critical reviews and Shubho Mahurat won the National Film Award for Best Feature Film in Bengali in 2003. Over the next couple of years, the actor had two releases, Bombaiyer Bombete (2003) and Badsha The King (2004). While Bombaiyer Bombete received negative reviews, it emerged to be a commercial hit but the later did not create any buzz the box office.
After a gap of nine years, the actor made his comeback to Bollywood film industry in 2005 with the critically acclaimed film titled Parineeta directed by Pradeep Sarkar. The film starring Vidya Balan, Saif Ali Khan, Sanjay Dutt, Raima Sen and Dia Mirza grossed more than 62.35 crore INR worldwide. The following year, director Dibakar Banerjee cast him in the comedy-drama film, Khosla Ka Ghosla alongside Anupam Kher, Boman Irani, Vinay Phatak, Ranvir Shorey and Parvin Dabas. The film, which won the National Film Award for Best Feature Film (Hindi) in 2006 was later remade in Tamil as Poi Solla Porom. His other two movies of the year, Shikar and Kranti, both Bengali films were average hits.
After 2006, Rajesh Sharma was out of action for three years before making a comeback in 2009 with the Bengali film, Chaa-e Chutti directed by Aniket Chattopadhyay. The following year, the actor had a single released, a black comedy Hindi film title Ishqiya starring Vidya Balan, Naseeruddin Shah, and Arshad Warsi. The film which was screened at the 34th Cairo International Film Festival got positive critical reviews. Following the success of Ishqiya, the actor next appeared in No One Killed Jessica, a biographical thriller film based on the true story of Jessica Lal murder case. The film starring Rani Mukerji and Vidya Balan won several awards and recognitions including the Most Entertaining Social Film at the BIG Star Entertainment Awards. It also emerged to be a commercial hit, grossing more than 58 crore INR. His other Hindi films of the year, Chillar Party directed by Nitesh Tiwari and Vikas Bahl and The Dirty Picture directed by Milan Lutharia were both commercial and critical hits with Chillar party winning the National Film Award for Best Children’s Film in 2011.
In 2012, the actor had 11 releases to his name, nine films in Bengali and two in Hindi. His first film of the year was a Hindi film, Chaalis Chauraasi directed by Hriday Shetty. The film starring Naseeruddin Shah, Kay Kay Menon, Ravi Kishan and Atul Kulkarni was an average earner. While his other Hindi film of the year, Luv Shuv Tey Chicken Khurana received positive reviews and emerged to be a commercial hit, none of his Bengali films garnered any attention at the box office. The following year, in 2013 the actor had a mixed year. While two of his Hindi films, Special 26 and B.A. Pass won critical acclaim, his other movies Shuddh Desi Romance and Ghanchakkar got mixed reviews. His Bengali films of the year too had contrasting results, while Ganesh Talkies did not fare well at the box office, Mishawr Rawhoshyo directed by Srijit Mukherji became one of the biggest hits of 2013.
Rajesh Sharma had a forgettable year in 2014 as none of his fours films viz. Pizza, Strings of Passion, Ekkess Toppon Ki Salaami, and the Bengali film Taan did not create any impact at the box office. The following year, the actor starred in four big banner films including Tevar, Tanu Weds Manu Returns, Bajrangi Bhaijaan and Dolly Ki Doli. While only Tevar bombed at the box office, the rest of the films not only garnered mostly positive reviews but also emerged to be a box office hits. The actor’s 2016 releases include Azhar, a film based on the life of former Indian cricket captain Mohammad Azharuddin and the biographical drama, M.S.Dhoni: the Untold Story directed by Neeraj Pandey. The actor started the year 2017 with a small role in the Vishal Mishra directed comedy film Coffee With D. The film starring Sunil Grover, Zakir Hussain, Dipannita Sharma and Anjana Sukhani failed at the box office. His other film of the year includes Irada, an eco-thriller directed Aparnaa Singh. The film features Naseeruddin Shah, Arshad Warsi, Divya Dutta and Sharad Keklar in pivotal roles.