The epidemiological characters of 142 patients, 121 males and 21 females, with duodenal erosions were evaluated. They were predominantly between 30 and 60 years old. During the observation time, 125 of them were complaining of dyspeptic symptoms while the remaining 17 had haematemesis and/or melena. Duodenal erosions were single in 9 cases, zonally distributed in 51 and disseminated in 82. Erosions were associated with duodenal ulcer in 25% of cases, with ulcer scar in 4%, and with gastric ulcer in 2%. The intake of alcohol, coffee, anti-inflammatory drugs and the smoking habit were similar in patients with duodenal erosions and the general population subjected to endoscopy. These results suggest a relationship between duodenal erosions and peptic ulcer.