The results of an endoscopic study of the incidence of gastritis and gastric cancer in gastric ulcer in a series of 112 patients 1 to 4 years (mean 2.6 years) after the initial examination are presented. Chronic antral gastritis was found in 48 % of cases and was mainly atrophic. In 10 cases both the antral and body mucosa were normal. In 11 cases the antral mucosa was normal before treatment and remained normal in most of them. During the observation period 5 patients died from other than gastrointestinal diseases. Eleven patients were operated on for complications or relapses of ulcer disease. Gastric cancer was found in 4 cases, the interval between the diagnoses of benign ulcer and cancer was from 1 to 27 months. Elevation of the blood carcinoembryonic antigen (CEA) level was found in 17 cases out of 56 examined and these values remained elevated in most cases at re-examination 3 years later.