Ten cases of gastroduodenal inflammation were diagnosed by endoscopy among a series of 196 children with evidence of Crohn's disease involving other regions of the intestinal tract. Endoscopic and histologic confirmation of upper gastrointestinal tract involvement was performed only in those cases with suggestive symptoms. The mean age at presentation in the 10 cases with gastroduodenal inflammation was 14.6 +/- 1.9 (+/- SD) years, with involvement identified at the time of initial diagnosis of Crohn's disease in five of the 10. Eight of 10 cases occurred in boys. The major presenting symptoms were weight loss in five cases, epigastric pain in three, and recurrent vomiting in two. Hematemesis and melena occurred in only one of the 10 cases. Endoscopic and histological evidence of mucosal inflammation was seen in all 10 cases. Three of 10 cases had noncaseating granuloma present in biopsies of the stomach or duodenum. Two cases also had endoscopic and histological evidence of esophageal involvement. All cases were initially treated with oral corticosteroids, and in each instance a good clinical response was noted. Sucralfate (n = 1), 6-mercaptopurine (n = 1), and H2 receptor antagonists (n = 3) were used as adjunct therapy. After follow-up for 2.7 years (range, 0.5-5.5 years), none of the 10 cases required surgical intervention. Therefore, at least in the short-term, the outlook for adolescents with gastroduodenal Crohn's disease appears to be good and their medical management need not differ from those patients with Crohn's disease involving only more distal portions of the small intestine.