Born in Colombo, Janaka Gunaratne is an all-rounder who bats right-handed and is a right-arm offbreak bowler. He made his first-class debut in the 2001 season.
Standing at 6 feet and 1 inch, Gunaratne has been a prolific run-scorer in the first-class arena, boasting of a decent batting average. An economical bowler, he also has the knack of taking regular wickets. In 2004, he went on to make his Twenty20 debut for the Chilaw Marians Cricket Club.