Fonseka started her acting career with stage dramas.
In 1963, she made her entry to stage dramas with "Noratha Ratha".
She achieved a significant milestone in her artistic career with Sasara Chetana in 1984, where she became both its director and producer.
She has directed two other films so far: Ahimsa in 1987 and Sthree in 1991.
She is also the aunt of another actress Samanalee Fonseka, sister-in-law of director Prasanna Vithanage and Karunaratne Hangawatte.