Rising to fame as one of the colorful (literally and figuratively) competitors during the first season of The Ultimate Fighter, Leben leaves the sport with a respectable record of 22-11.
"It's slowly registering," Leben (12-10 UFC) told MMAjunkie. "But the more I sit back and reflect, this is the right decision to make. It's time to move on and make that next step."
He revealed that he was contemplating retirement before his most recent fight, in which he quit on the stool after the first round against Uriah Hall.
"I was actually out," he said. "I truly thought the referee had stopped the fight, and I was surprised when they started getting me ready to go out for the next round."
Concern for getting hurt once again along with the realization that getting by in today's UFC requires more than just the incredible toughness he is known for, are what ultimately helped him make the decision.
"As I get older, my body is starting to slow down a little bit," said Leben, who has lost four consecutive contests. "It's not that I'm the oldest guy, but I've been doing it for a while. Things are starting to slow down, and I want to get out while I can still use everything."
Outside the cage, Leben also achieved more than his share of notoriety. He was arrested two times for DUI and also admitted that he was addicted to pain killers and alcohol. Additionally, he failed two post-fight drug tests for PED's following cards in which he was a headliner. In 2012 he entered rehab to deal with the issue.
He claimed that the support of his family has been key in helping him find balance in his life. Now that he will no longer actively compete, he says he will focus on coaching in San Diego.
"The sky's the limit as far as what I can do," he said. "For me, the main thing is remembering that just because I'm retiring doesn't mean I'm dead."
Chris Leben leaves the UFC as the middleweight who competed the most time within the organization, with 19 fights. And with 1,791 strikes landed, he also leads the division in that category as well.
As for whether or not he will be able to stay retired, Chris Leben doesn't think that will be an issue.
"You kind of know when it's time," he said. "And having been with the UFC for so long, if I'm not fighting in the UFC, I'm not fighting. Also, I'm not afraid to admit, we all have our time in the light. And it's my time to move on to different endeavors."