Kampmann (20-7) is most well known for his 17-fight stint in the UFC, where he posted an 11-6 record from 2006 to 2013, defeating the likes of Carlos Condit, Thiago Alves and Thales Leites while competing in both the middleweight and welterweight divisions.
"I’ve known for a while," the 33-year-old Kampmann said of retirement in the initial report published by UFC.com. "I just haven’t really made it official. I’m not sure why."
A two-time Fight of the Night, two-time Submission of the Night and one-time Knockout of the Night recipient, Kampmann represented an early example of the modern, well-rounded mixed martial artist.