Karthik was first introduced by Bharathiraja in the film Alaigal Oivathillai. He has received the Best New Face Award from the Tamil Nadu Government in 1980.
He has received the best actor for three consecutive times by Tamil Nadu government. He is popular with the audience for sense of humor and was involved with several small comedy scenes in most of his movies. His cameo in Mouna Ragam was very well received by the audience. During his later years, he formed a partnership with Goundamani in many comedy movies. His pairing with Rambha was a hit with audience as the pair provided good hits in the nineties.He made a comeback into Tamil cinema with movies like Raavanan and Maanja Velu and (pulivesham). Karthik's completed films, Garvam, is yet to be released.