Carcinoma of the gastric stump in patients who have undergone resection for duodenal and gastric ulcer represents a rare event which poses considerable diagnostic and therapeutic problems. 7 personal cases are examined, particular attention being paid to the utility of endoscopy, together with sampling for cytological and histological examinations, by comparison with radiology. Endoscopy in the present cases have confirmed the high positivity obtainable with transendoscopic cytological sampling using the brushing technique. The technique should therefore become routine in the study of patients undergoing gastric resection.