As part of a retrospective study, 1775 patients, who were treated in 1991 and 1992 in the operative ICU for a minimum of three days, were examined regularly regarding methicillin resistant S. aureus (MRSA) and the consequences thereof. An analysis of the data (age, sex, previous illness, length of hospital stay before the ICU, antibiotics before the ICU, invasive diagnostic process, immunosuppressives, diagnosis at admittance) showed no significant statistical risk of MRSA. An almost constant probability of MRSA detection during the ICU stay was shown. Patients with MRSA had a significantly higher mortality rate and frequent septic complications. The incidence of MRSA in operative intensive care medicine increases the rate of complications, mortality and costs. The most important counter measures are strict hygiene and early specific chemotherapy.