Wijekoon held the Sri Lankan National Badminton Championships singles title for nine years (1983–1987 and 1989–1992).
He also participated the World Badminton Championships in 1989 in the men's singles losing to Kim Hak-kyun of South Korea 7:15 and 7:15.
In his home country, he won nine titles in the men's singles at the Sri Lankan National Badminton Championships between 1983 and 1992.
Even now, as Director of the stock brokering firm Asia Securities he still plays in Sri Lankan National Badminton Championships, making his 32nd appearance in 2007.
At the age of 38, unseeded Wijekoon beat the bottom seeded Udaya Wanigasinghe to make a long due singles quarter finals berth.