In 1937 he graduated Kaunas Highs physical education courses, taught in Higher Technical School. Baltrūnas became interested in basketball in 1935 when he met with the basketball coach from the U.S. Konstantinas Savickas. He was member of Lithuania national basketball team (1936–1940) and participated in two EuroBaskets: EuroBasket 1937 and EuroBasket 1939. He won two gold medals during both competitions. In 1944 he moved to Germany, in 1949 he settled in Australia. In 1950 he organized Lithuanians basketball championship in Melbourne for the first time, established Lithuanians sports club "Varpas" and was physical education chairman. In 1949-1953 he was Victoria state and in 1955 Australia national basketball team coach, later he worked as physical education teacher at Swinburne Technical School in Hawthorn, Victoria. He also firmly contributed in popularizing volleyball in Victoria state. Leonas Baltrūnas once said: