Ada Smolnikar took up gymnastics in elementary school and, during the trials for the 1952 Helsinki Olympics, qualified to represent Yugoslavia in the tournament as its eighth and final member, alongside her friend Sonja Rožman. There, the nation was eighth in the team portable apparatus and 11th in the team all-around, while Smolnikar had her best finish in the floor exercise with 80th. Her next stop was the 1954 World Championships, where Yugoslavia was 11th out of 15 nations in the team all-around. She retired from active competition in 1956, as her country did not send a team to the Melbourne Olympics.