The robbery happened around 11:10 a.m. Sunday inside the Macy's at Northridge Fashion Center, according to the Los Angeles Police Department.
It's unclear what the thieves were able to get away with, but at least one display case with cologne was damaged.
At least 10 men dressed in dark clothing were involved in the theft, police said.
No injuries were reported.
The L.A. area has been hit with a string of similar thefts - some happening at luxury retailers.
Last month, L.A. Mayor Karen Bass and several local law enforcement agencies announced the formation of a task force to address organized retail crime.