We evaluated the usefulness of adding weekly methicillin-resistant Staphylococcus aureus (MRSA) screening to our established admission screening and clinical sampling in 4 acute care units of a university hospital. Our results suggest that weekly MRSA screening allows the detection of 56.1% of all cases of hospital-acquired MRSA carriage. These cases would have remained undetected had admission screening and clinical sampling been the only types of surveillance in place.