"The Hills" star Stephanie Pratt pleaded not guilty to misdemeanor DUI in court on Friday. Her lawyer says she will enroll in a 30-day residential rehab facility.

Pratt, 23, was arrested in October after celebrating Holly Montag's birthday at Empire in Hollywood.

Find out how much "The Hills" stars and other reality TV celebs earn

If convicted, Pratt faces up to six months in jail and a $1,000 fine.

This is not Pratt's first run-in with the law. In 2006, she was arrested for shoplifting from a Neiman Marcus in Honolulu, where she was working as a production assistant on "Lost."