The crash occurred near Ventura Boulevard and Oakdale Avenue at about 9:45 p.m. Thursday. Authorities said two cars collided head-on, trapping passengers in their vehicles.
"Fire department dispatched a full physical rescue assignment to extricate the people out of their vehicle. We were able to get the people out of the vehicle in short order," said Battalion Chief Brian Schultz with Los Angeles County Fire.
All four patients were listed in fair condition with minor injuries. One of those patients was set to be booked for DUI after being released from the hospital.
Police are still working to determine the cause of the crash.