An outbreak of skin infection caused by a beta-lactamase-negative strain of methicillin-resistant Staphylococcus aureus (MRSA) occurred during a five-week period in a newborn nursery. Twelve babies, two mothers and two members of staff were involved. One baby had a diagnosis of staphylococcal scalded skin syndrome and two others required treatment with antibiotics. The infecting strain produced exfoliative toxin A. It was thought that it had been introduced from a different maternity unit by a nasal carrier. Laboratory investigations tended to support this hypothesis.