Ernő Gubányi started playing handball in Veszprém in 1965, in the team of the Chemical High School. In 1968 he moved to Budapest to Vörös Meteor, first becoming a player in the youth team, and then a year later in the senior team. In 1973 he transferred to the Tatabányai Bányász team. Together with Tatabánya he was Hungarian champion in 1974, 1978, 1979, and 1984, and won the Hungarian Cup in 1978. In 1970 he became the league’s top scorer as a player for Vörös Meteor.
Between 1972 and 1980 Gubányi appeared in the Hungarian national team a total of 159 times. He was a member of the Hungarian national team that placed 6th at the Olympics in 1976, 4th at the Olympics in 1980, 7th at the World Cup in 1974, and 9th at 1978 World Cup.
In the last two years of his sports career Gubányi played in the VfL Freidenbeck team in West Germany.