The authors studied 7 cases of peptic ulcers (2 gastric and 5 duodenals) in patients whose ages ranged between 3 and 13 4/12 years. They represented 0.5% of hospital inpatients. A history of acetyl salicilic acid ingestion was present in 3 of the cases. In 2 of the cases emotional factors were associated. Initial symptoms were distributed as follows: abdominal (4), hematemesis (2) and melena (1). The clinical course was favorable for 5 of the patients; in one of them signs of bulboduodenitis became evident in the fourth month; in another one the clinical signs persisted and a new ulcer appeared 4 months after the initial diagnosis. High levels of gastrin were found in this case. The importance of gastroduodenal fiberendoscopy in infancy for the diagnosis, histological confirmation and follow-up of peptic ulcer is emphasized.