Muntz was born in Voorschoten. As an amateur, he won three Dutch Amateur Championships and two Dutch Stroke Play Championships and became the first Dutchman to win The Amateur Championship. He also represented the Netherlands in the Eisenhower Trophy in 1990 and 1992 before quitting his law and psychology studies at Leiden University to turn professional in 1993.
Muntz played on the Challenge Tour and the Southern Africa Tour. He became a member of the European Tour in 1995. In 1999 he lost to Warren Bennett in a play-off for the Scottish PGA Championship. In 2000 he won the Qatar Masters to become the first Dutchman to win a European Tour event since the tour was founded in 1972 and the first to win a front rank European professional tournament since Joop Rühl won the 1947 Dutch Open.
Muntz represented the Netherlands in the WGC-World Cup in 1999.
|The Open Championship||CUT||CUT||DNP||DNP|
|The Open Championship||DNP||DNP||DNP||DNP||DNP||DNP||DNP||DNP||DNP||CUT|
DNP = Did not play
CUT = missed the half-way cut
"T" = tied
Green background for wins. Yellow background for top-10.