Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infections. Healthcare professionals in the United States should develop programs to prevent transmission of this organism within their institutions. Aggressive control efforts are justified for several reasons: (1) the incidence of nosocomial MRSA reflects the general effectiveness of infection control practice; (2) MRSA do not replace susceptible strains but instead increase the overall rate of nosocomial S. aureus infections; (3) MRSA infections cause substantial morbidity and mortality; (4) serious MRSA infections must be treated with vancomycin. Thus, in hospitals with high rates of MRSA, use of this antimicrobial agent increases, which in turn may increase the risk for selecting vancomycin-resistant enterococci. Hospitals have used numerous different approaches to control nosocomial spread of MRSA. Staff should choose a control method based on the prevalence of MRSA in their institution and in their referring facilities, the rate of nosocomial transmission of MRSA in their hospital, the risk factors present in their patient population, the reservoirs and modes of transmission specific to their hospital, and their resources. Any MRSA control plan must stress adherence to basic infection control measures, such as hand washing and contact isolation precautions. In addition, decolonization of patients and staff, control of antimicrobial use, surveillance cultures, and molecular typing may be helpful adjuncts.