De Silva made his debut for Ceylon in 1966-67 and played in most Sri Lankan teams thereafter until the mid-1980s. He took part in the 1979 cricket World Cup where Sri Lanka recorded their first top-level international victory, beating India by 47 runs. De Silva took three wickets for 29, including Dilip Vengsarkar and Mohinder Amarnath, as India crashed to 191 all out. He took his best first-class figures on the 1979 tour of England when he took 4 for 13 and 8 for 46 in the innings victory over Oxford University.