We hope that standardized nomenclature for identifying epidemic MRSA strains prevalent in Canadian hospitals will be helpful to physicians and infection control practitioners attempting to understand and control the spread of the organism in health-care facilities. It is anticipated that as MRSA continues to evolve in Canadian health-care facilities other strains may be recognized as "epidemic"; as these strains become better characterized they may be added to those designated above. Laboratory physicians and infection control personnel are invited to submit strains that may warrant characterization and designation as a Canadian epidemic strain to the Laboratory Centre for Disease Control, Health Canada, Winnipeg, Manitoba.