Judit Ágoston-Mendelényi took up fencing in 1951 and found her first fame in 1957, when she won team foil gold at the Universiade. The high point of Ágoston-Mendelényi’s career was probably the 1964 Olympics, where she won team foil gold. At the World Championships, Ágoston-Mendelényi won three team medals – silvers in 1961 and 1971 and bronze in 1969. Ágoston-Mendelényi’s only individual medal of note came at the 1963 Universiade, where she won individual foil bronze, and a team silver. Domestically, Ágoston-Mendelényi did not win an individual title, her best finish at the Hungarian championships a third in 1969, but she won three Hungarian team foil titles in 1958, 1964 and 1968. Ágoston-Mendelényi graduated from the Hungarian College of Physical Education (now Faculty of Physical Education and Sport Sciences of Semmelweis University) in 1960 as a physiotherapist and physical education teacher and from 1969-72 worked as a physical education teacher with Central Sports School in Budapest. From 1975-85 she was the fencing coach with Budapesti Vasutas Sport Club (BVSC). Her husband Tamás Mendelényi was also a world class fencer, who won a team sabre gold at the 1960 Olympics.
Hungary