Data from around the world verify the escalating incidence of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Since MRSA are spread primarily on the hands of health care workers, rates of infection are a function of infection control activities within institutions. Moreover, infections with MRSA are serious and often life-threatening. Thus, there are compelling medical and ethical reasons to invest in control measures. Currently available data suggest the efficacy of three measures: (a) identification of the entire patient reservoir (cases and carriers) for purposes of isolation; (b) strict handwashing between patients to prevent transmission; and (c) treatment of the carrier state in health care workers and patients during periods of high infection rates with safe and effective topical agents such as mupirocin.