István Barta started swimming in Budapest as a water polo player and breaststroker. In 1926 and 1926 he won national titles in the 100 breast. But greater success came as a goalkeeper in water polo, winning national championships in 1923-24, 1928, and 1930-1932. His Olympic career began with a fifth place in 1924 at Paris, winning the silver medal behind Germany at Amsterdam in 1928, and winning gold in 1932. In 1926, 1927 and 1931 he was European champion with the Hungarian team. Barta was a member of the national team for 50 international matches, even though, in the early 1930s he was the head of a large textile company, so he could not easily participate in matches abroad, which paved the way for the new upcoming goalkeeper György Bródy. At times, Barta adopted the German name Berger.