When he was 12-years-old Osvaldo Cochrane Filho began swimming for Fluminense in his home city of Rio de Janeiro. In 1952 Cochrane joined their water polo club, being part of the team that remained undefeated in 104 games from 1952 to 1961. From 1955 to 1971 he also played for the Brazilian national water polo team, which saw him compete at the 1964 Tokyo Olympics. Cochrane ended his competitive career after the 1971 Pan American Games and later worked for the Jockey Club Brasileiro, where he served as their Vice-President for 12 years.