The "Boyfriend" singer posted a photo of himself alongside the controversial rapper, 25, Monday.
"Studio, me and CB did 1 for the fans," he wrote.
Bieber, 20, has been working on new music, and posting clips to his Instagram page in the past few weeks. He has also been dealing with several legal issues, including an outstanding investigation in which he has been accused of vandalizing a neighbor's house with eggs.
Brown has had his fair share of troubles, too. Until earlier this month, he'd been in jail for more than two months for a probation violation stemming from the 2009 incident in which he assaulted then-girlfriend Rihanna.
Since his release, however, he has been promoting his new music, including the song "Loyal," which features Lil' Wayne and Tyga.