He was a squad member at CAN 1974 where Zambia reached the final only to lose to Zaire after a replay. When Dick Chama retired, Simwala was named captain and he led Zambia to the 1976 East and Central Africa football tournament where they lost the final 2–0 to Uganda. He was part of Zambia's Olympic Games squad at Moscow 1980 and played all three games as Zambia bowed out in the first round. His last game for Zambia came on 12 December 1980 in a 1–1 draw with Kenya during that country's Independence celebrations after which he announced his retirement from football to leave room to young players and took up the coaching job at Rhokana stadium.