Ferenc Keserű (often called Keserű I) began competing in swimming and water polo in 1916. He had 66 appearances with the Hungarian water polo national team from 1921-32, although he played for clubs in France and Belgium in 1927-28. Just like his brother Alajos (Keserű II), he started his Olympic career in 1924 at Paris with a fifth place, won the silver medal behind Germany in Amsterdam in 1928 and won gold in 1936. With the Hungarian team he was a three-time European champion (1926, 1927, 1931) and two-time Hungarian champion (1923-24). Ferenc Keserű was also a successful swimmer and Hungarian Champion as an open-water swimmer – 1921 individually and 1923 in the team event. From 1933-35 he was head coach of the Hungarian water polo team and later a referee. Professionally, he earned a law degree (PhD) from the Budapest University and worked as a lawyer for the Central Court of the Town Hall. During World War II he was principal officer in the accounting department.
Hungary