As a professional soldier, Gusztáv Kálniczky achieved outstanding results in épée and foil. Initially he competed with the Békessy Béla Vívó Club in Debrecen and then, on moving to the capital, continued his career with the Honvéd Tiszti Vívó Club. As a member of the latter club he won the épée team championship title four times (1929-1932) and the foil twice (1931-1932). He competed in épée at the 1928 Olympics, where he was eliminated in the first round and finished fifth with the team. At the European Championships as a member of the Hungarian épée team he won one silver (1931) and one bronze medal (1929). In 1934 he retired with the rank of captain and moved back to his estate and began farming.