Janaki became a moderately successful actress in the late 1940s. She starred in more than 25 movies including "Mohini" (1948), "Raja Mukthi", "Velaikaari", "Aiyiram Thalaivangiya Aboorva Chintamani", "Devaki" and "Marudhanaattu Ilavarasi". Many of her hits were in films where her future husband, Ramachandran, played the lead role, and she played either the heroine ("Marudhanaattu Ilavarasi") or a major supporting role ("Raja Mukthi," "Velaikkaari" etc.). The first film where the two acted together was "Mohini" (1948), which was the first real blockbuster for both of them.