Patients with skin diseases caused a spread of methicillin-resistant Staphylococcus aureus (MRSA) to 17 patients in our Department of Dermatology, because of their heavily scaly skin. Patients with severe dermatosis are regularly treated with dicloxacillin. The resistance of bacteria strain concerned suggests a selection because of the use of dicloxacillin in the Department. The strain is sensitive to gentamicin, which differentiates it from strains imported from abroad. Increased hygienic precautions, isolation of infected patients, staff and management efforts and a close contact with the microbiologists prevented MRSA from spreading to other hospital wards.