Mamta Mohandas started to work with Hariharan's Malyalam movie Mayookham in 2005. This movie was a flop but Mamta was noticed by all because of the character she played and then appeared in a supporting role in Bus Conductor. She acted in Madhuchandralekha, Adhbutam and Lanka. She did a Tamil movie Sivapathigaram opposite Vishal Reddy. Her singing debut was in the movie Rakhee and she received the Filmfare Award for the Best Playback Female Singer(2007) in Telugu. In the Kollywood industry she sang the title song for Kaalai. She was a supporting actress in Yamadonga directed by SS Rajamouli, which proved to be a big hit. She also sang a couple of songs for this movie.