The 25-year-old singer was hosting a pre-VMA party when the shooting happened.
READ: CHRIS BROWN 'OBSESSED' WITH KARRUECHE TRAN AND RIHANNA
Leaked video footage shows partygoers being ordered by bouncers to 'get dow' after gun shots were fired, injuring three people.
Chris was not harmed during the attack, but later tweeted his 'disappointment'.
He wrote: "It is disappointing that we as a society cannon have fun or enjoy ourselves without any altercations sometimes. Miss me with the b******t.'
READ: KARRUECHE TRAN OPENS UP ABOUT 'BATTLE' WITH RIHANNA
A Twitter user believed to have been at the nightclub in LA when the attack took place wrote: "Literally can't believe what I just witnessed. Someone tired to fire shots at Chris Brown at 1oak. Speechless.
"Prayers to all those harmed by this. Honestly still in disbelief this happened."
An Australian model, Simone Holtznagel, also took to Twitter to say she and fellow model Chloe Lloyd were forced to hide in the toilet as the gunmen attacked.
READ: KARRUECHE TRAN CONTINUES ANTI-BODYSHAMING CAMPAIGN WITH STRETCH MARK BELFIE
She said: "Me and @MOANN sort refuge in a toilet cubicle as rifles targeted Chris brown & bieber outside. #usa (sic)'.
One of the victims was Suge Knight, founder of Death Row Records. Another of those harmed is said to be in a 'critical' condition.