Notably fought for Strikeforce, and he has won the RINGS Free Fight Dutch Heavyweight Championship.
He made his professional debut on February 18, 1996, winning via submission against Tjerk Vermanen.
He has also kickboxed professionally.
His younger brother, Alistair Overeem, is also a fighter, and the two often train together.
He made headlines on February 24, 2001, when he defeated Randy Couture.