She won gold medals in the 200 m breaststroke at the 1947 European Aquatics Championships and 1948 Summer Olympics.

[3] Nel van Vliet was born in Hilversum and learned to swim only around the age of 16 (c. 1942), during World War II.

She improved significantly after the end of the war, setting 13 world records in various breaststroke and medley relay events in 1946–1947, and winning national championships in 1946 and 1948.

To win the 1948 Olympics, it was sufficient for her to swim eight seconds slower than her personal best time, that is, the world record.

Van Vliet was the first top swimmer raised by the famous Dutch coach Jan Stender.