He won the gold medal at the 1948 Summer Olympics in London, Great Britain.

He returned four years later to defend his title at the 1952 Summer Olympics held in Helsinki, Finland but failed, only managing to finish third for the bronze medal.

On 14 July 1948 he threw 59.02 metres, beating Erwin Blask's official record from 1938 by two centimetres.

)[3] On 4 September 1949 Németh improved the world mark to 59.57, beating both the official and the unofficial record.

His son, javelin thrower Miklós Németh, also won an Olympic gold medal.