The 'Believe' hitmaker scaled the metal railings after spotting a group of young females waiting outside his Los Angeles recording studio on Tuesday (27.05.14) evening, and happily posed for pictures and signed autographs.
The 20-year-old singer - who wore a white t-shirt, jeans and a heavy gold chain - even gave one of the fans a kiss after climbing the barrier.
Justin agreed to paparazzi requests to pose for pictures, but added: "I just wanna say hi to my fans."
The troubled star is said to be "trying to be a better person" after a number of recent controversies, including being arrested for driving under the influence (DUI) and getting into altercations with members of the public for allegedly taking pictures of him.
And Justin, who donated $545,000 to AIDS/ HIV research at the amfAR's 21st Cinema Against AIDS Gala in Antibes, France last week, recently urged fans not to believe everything they read about him and insisted he wants to be a good person.
He tweeted: "My mom raised me to be kind to others. I get judged, harassed, and I try to take the high road. Sometimes it isn't easy. But we keep trying.
"I will continue to be the man my mother raised. I love people and I will try to be kind even when things are not fair. Don't believe rumors. (sic)"