An audit of hypoglycaemic admissions among diabetic patients to Baragwanath Hospital, Soweto, South Africa was carried out prospectively during a recent 5-month period. A total of 51 episodes of biochemically confirmed hypoglycaemia (blood glucose < 2.2 mmol l-1 with coma or pre-coma, and requiring intravenous glucose) were observed in 43 patients. There was a wide range of ages (22-88 years) and an excess of males (27 M:16 F). Fourteen (33%) cases were associated with sulphonylurea (gliclazide) treatment. Doses of insulin or sulphonylureas were not excessive. The major cause precipitating the event was a missed meal (36%), though alcohol (22%), gastrointestinal upset (20%), and inappropriate treatment (18%) were also important contributory factors. Following recovery from the event, doses of drugs or insulin were frequently reduced, and three patients were successfully taken off insulin, and six off gliclazide. There was no mortality in this series, and no obvious long-term morbidity. We conclude that severe hypoglycaemia is a frequent and important acute diabetic complication in Soweto. Patient education and care in prescribing for Type 2 diabetic patients may help reduce its occurrence and severity.