One thousand seven hundred and fourteen Black Zimbabwean patients underwent upper gastrointestinal endoscopy. Demographic details of the patients were analysed. A randomly chosen cohort of 50 patients with duodenal ulceration was compared to age and sex matched controls regarding lifestyle and H. pylori infection. Five hundred and sixteen patients had active duodenal ulcers, giving a crude prevalence rate of ulceration of 456 per 100,000 new hospital cases. There is a difference from the disease in Western countries in several respects. The incidence appears to be increasing in Zimbabwe. There was no significant difference between ulcer patients and controls in their association with alcohol consumption, cigarette smoking, urban residence and salicylate ingestion (p > 0.1), Ulceration was most strongly associated with H pylori gastritis compared to control (p < 0.001). Duodenal ulceration was most prevalent in the 21 to 30 year age group. The overall male to female ratio was 4.7:1. A significant proportion of patients had persistence of ulceration after a standard course of Cimetidine. Pain did not always correlate with presence or absence of ulcers.