A retrospective review of breast abscesses during a 10-year period was performed. Only 8.5 per cent (6/72) of patients were in the puerperium. Peripherally sited abscesses were predominantly staphylococcal in origin, incision and drainage was effective treatment in all. By contrast, a subareolar abscess yielded a higher proportion of anaerobic bacteria and 46 per cent (13/28) of these patients had duct ectasia. We conclude that in present day practice a breast abscess is more likely to be related to duct ectasia than to the puerperium, and that patients with anaerobic infection or subareolar abscesses should be assumed to have duct ectasia and may require excision of the major duct system (Hadfield's procedure).