Radha started her career with Bharathiraja's 'Alaigal Ooivathilai'. Gopurangal Saivathillai proved her acting talents. She played a powerful role as a second wife of Mohan and matched the national award winner Suhasini (who played the first wife) in this movie. Radha played a small role in Tik Tik Tik, a Kamal Haasan starrer. Tik Tik Tik played a significant role in her career. She then starred in a number of Kamal Hassan movies like Oru Kaithiyin Diary, Thoongathey Thambi Thoongathey, Kathal Parisu and Jappanil Kalyanaraman. Her close friend and mentor, actress Suhasini Maniratnam helped her in improving her make-up and took special care by voluntarily opting to hairdress Radha whenever they acted together.
Her major break came from her mentor Bharathiraja. Radha was cast a movie opposite Sivaji Ganesan. Muthal Mariyathai released in the year 1985. After Muthal Mariyathai, she got a number of challenging roles including in movies like Nyaya Tharasu.
Her sister Ambika is also a very popular actress. They acted together in films like Enkeyo Ketta Kural, Kadhal Parisu, Anna Nagar Mudhal Theru, Idhaya Kovil and Vellai Roja.
The two sisters were at the zenith of their beauty and fame when they acted in Kadhal Parisu. They put up electrifying performances that easily overshadowed even Kamal Hasan, the senior actor paired opposite to them. Ambika and Radha managed their careers very carefully, seldom directly competing in the same turf. They both used the Tamil movie industry to launch their careers, but spent only a minority of time in Tamil once their success & fame spread across the South. Ambika acted in more Kannada and Malayalam movies, quickly getting to the top-2 spots in both markets. Radha conquered the undisputed top spot in Telugu movies for almost 5 years consecutively between 1984 and 1989. Ambika and Radha were both very selective about taking up roles in Tamil movies once they became successful, rejecting many offers and only pairing with the top actors and directors of the time. It was very rare to see both the sisters in the same movie after their early years in Tamil. So it was indeed a dream come true for fans when Kadhal Parisu hit the screens, especially since both sisters played the roles of very glamorous and highly desirable women in the movie.