Ion Gârleșteanu played rugby football for the Romanian team that won a bronze medal at the 1924 Paris Olympics. There were only three teams in the 1924 Olympic tournament and the Romanians won the bronze medal despite losing both of their matches badly, losing 61-3 to France, and 37-0 to the United States. Gârleșteanu played for Stadiul Român in București and played both scrum-half and fly-half at the Olympics. He was capped four times for Romania, playing against France and Czechoslovakia in 1927.
Gârleșteanu later worked as a civil servant in the architecture department of the municipality of Ploesti. He died by suicide in June 1939, after jumping from a window from the second floor of city hall.