During the course of one year all (382) strains of staphylococci isolated in significant culture from urine specimens were typed by the Baird-Parker method. Staphylococcus aureus accounted for only 63 (16%) of the infections. Novobiocin-resistant micrococcal infection occurred predominantly in young women but also in children of both sexes; it was not restricted to M3. To try to detect possible sources of micrococcal infection other than faeces the normal flora of the throat, urinary tract, and vagina of young women was studied. Novobiocin-resistant micrococci were rarely found. Previous reports that micrococci are the second commonest urinary pathogens in young women in domiciliary practice were confirmed. The laboratory records of patients with these infections suggested that they respond well to treatment and that recurrences are usually due to a different organism.