The former OC actress is currently out on bail after being booked on suspicion of DUI, driving without a valid licence and possession of marijuana in West Hollywood on December 27.
She was spotted paying a visit to the Good Shepherd Catholic Church in Beverly Hills, reportedly looking "deep in thought".
A witness told TMZ: "Mischa came out of the church looking very pious, wearing a white, virginal dress. She was carrying a church brochure."
Prison Break star Lane Garrison visited the same church in December 2006 after he was involved in a car crash which left a 17-year-old student dead. He is now serving a 40-month jail sentence for vehicular manslaughter.
Lindsay Lohan has also been spotted there, while Paris Hilton's parents attended mass while she was behind bars last May.