Cops were called to Samantha Ronson's house Monday night after someone broke into her garage.
We're told the 911 call came in just before 7 PM. Law enforcement sources tell TMZ ... the burglars didn't make it inside Sam's house.
It's unclear what -- if anything -- was taken.
As you probably know, Sam lives right next to Lindsay in Venice, CA.
UPDATE: Law enforcement sources tell us ... one item was taken from Sam's garage, worth about $1,000.