Stephanie Pratt of MTV’s The Hills was arrested for a DUI this weekend, reports TMZ.

Law enforcement says Pratt was busted Sunday morning at 3:45 AM PT in Hollywood.  She was taken into custody with her bail set at $5,000.

A source close to Stephanie tells TMZ she had just left Holly Montag‘s birthday party when she was pulled over.  The source says cops watched Stephanie get in her car and were waiting to bust her.

Stephanie was released Sunday afternoon after posting bail.