Prashanth rose to stardom with Shankar's romantic comedy Jeans (1998) in which he played a dual role alongside Aishwarya Rai.

He went on to star in several successful films including Chocolate (2001), Majunu (2001), Thamizh (2002), Virumbugiren (2002), Winner (2003), Shock (2004) and London (2005).

[7] He studied Computer Graphics and Multimedia and went to Trinity College of Music in London before embarking on an acting career.

He then appeared in the Malayalam film Perumthachan written by M. T. Vasudevan Nair where he played the son of the title character.

In 1999, he acted in romantic family dramas movies, Poomagal Oorvalam, Jodi, Hello and Aasaiyil Oru Kaditham.

Featuring him alongside actresses and comedians, the show was held in Malaysia, Singapore and then at Wembley Arena in London.

[22] In a sudden change of strategy, Prashanth chose to focus on acting in films produced by his father Thiagarajan for the family's production studio, Lakshmi Shanthi Movies.

[28] Other films including the action drama Aayudham (2005) and comedy London (2005), similarly met with a tepid response at the box office.

[31] Prashanth next signed on to appear in Susi Ganesan's village action story Sakkarai in October 2004 only for the film to be discontinued after a grand launch ceremony.

[36] Morgan's Taxi Driver alongside Reemma Sen and Namitha was also planned amidst much hype, with the team announcing schedules in the Middle East as well as marking the debut of music composer G. V. Prakash Kumar; though the film was later shelved.

[38] The actor's other projects during the period which were announced but never made included Raghuraj's Jockey, Mukil's Arun Weds Harini and Cheyyar Ravi's Vithagan.

Jambhavan, which released in September 2006, had gone through production hassles notably after the lead heroine Nila had a spat with the producers and delayed the film's shoot.

[39] Shiva Shanmugam's Thagapansamy which featured Prashanth in the role of a village do-gooder, with Pooja and Namitha in other pivotal characters.

Featuring no lead heroine, the film told the tale of an estranged family with Thiagarajan, Saranya and Uma also in the cast and a critic noted that "as a brother and a bitter son, Prashanth has churned out what is arguably one of his better performances till date.

[43] In early 2007, Thiagarajan approached Karunanidhi with the intention of making a film on his adaptation of the Ponnar Shankar epic that he had written in the late 1970s.

[46] In September 2008, Thiagarajan announced that he would remake his successful 1983 film Malaiyoor Mambattiyan, with Prashanth portraying the lead role of a Robin Hood-esque figure.

[49][50] The film took a good opening at the box office, but it however petered out to do average business commercially and due to its big budget, failed to recover costs.

[52][53][54] Moreover, in November 2013, Prashanth announced that he had registered the title Jeans 2 and was completing the pre-production works of a sequel to the 1998 film.

The film was set to be directed and produced by Prashanth's father Thiagarajan, who revealed that production would begin in May 2014 and that they were trying to bring members of the original team back for the venture.

[58] Prashanth's latest films have been synonymous with remakes, expansive press releases and long production delays.

The film went through changes in cast before being released in December 2018 to mixed reviews from critics and a below average opening at the box office.

[68] After years of production delays, the film, titled Andhagan, released in August 2024 to generally positive reviews, with many branding it as his long-overdue comeback.