The fighter announced the news on his Twitter page.
The 31-year-old made a big splash in the early part of his UFC career, winning four straight, including a memorable head kick knockout over Mirko Cro Cop that vaulted him into a championship match against Randy Couture.
Gonzaga (11-6) lost that UFC 74 title bout via third-round TKO, and he never recovered the momentum that he once had. Including that Couture loss, he's just 3-5 in his last eight fights, with wins over Justin McCully, Josh Hendricks and Chris Tuchscherer. But Gonzaga had trouble with elite fighters, dropping bouts to Fabricio Werdum, Shane Carwin and Junior Dos Santos, all via KO or TKO.
Prior to his UFC 121 fight against Brendan Schaub, he attempted to retool his training, spending some time at Xtreme Couture in Las Vegas, but to no avail. He fell short in a three-round decision loss.
"Thanks for all your support," Gonzaga wrote in his tweet. "Back to normal life and BJJ forever."