Although internationally Jorma Kortelainen was more successful in cross-country skiing, domestically he was more successful in rowing. Kortelainen won a relay silver in his only international cross-country tournament, the 1956 Olympic Games. Four years later Kortelainen competed at the Olympic Games again, but this time in the Summer Olympics in rowing. At Rome he was eliminated in the single sculls, in the repêchage of round one. In rowing he was also eighth at the 1962 World Championships and tenth at the 1963 European Championships in single sculls. At the Finnish cross-country skiing championships Kortelainen won one individual title in 1963 and one silver (1955), both in the 15 km, and four relay titles (1956, 1960, 1963, 1966) and two relay bronzes (1962, 1968). In rowing Kortelainen won seven Finnish titles in the single sculls (1960-1963, 1965, 1967, 1968) and five Finnish titles in the double sculls (1961-1963, 1971, 1973). He also won Nordic Championships in single sculls in 1961 and 1963 and in double sculls in 1959. After his sporting career Kortelainen worked as a rowing coach.