Tamás Molnár belongs to the generation of Hungarian water polo player who was able to build on the great successes of the 1950s from the 1990s. In 1998 he was elected to the Hungarian water polo player of the year.
Tamás Molnár belongs since 1997 to the Hungarian water polo team. He belonged to the team that the European title in 1997 and won the 1999 World Cup and in between was second in 1998.
At the Olympic Games in Sydney in 2000, the Hungarian team with Tamás Molnár won. He finished third at the European Championships in 2001 and won the 2003 world title. In Athens at the 2004 Olympics, he helped to defend the gold medal of 2000. In 2005 he won silver at the World Championships. At the Olympic Games in 2008, the Hungarians won the finals against the team from the United States. For Molnár it was the third Olympic victory in a row.