A review of the endoscopy reports and pathology results from esophagogastroduodenoscopy (EGD) of all patients with familial adenomatous polyposis (FAP) undergoing such an examination was performed. Two hundred forty-seven patients were identified, with an overall prevalence of duodenal adenomas of 66 percent and of fundic gland polyps of 61 percent. Analysis of our more recent experience (1986 to 1990) shows the prevalence to be 88 percent and 84 percent, respectively. A normal-appearing papilla was adenomatous in 50 percent of cases. No case of periampullary carcinoma developed in patients under surveillance. Routine EGD is indicated for patients with FAP. Duodenal adenomas and fundic gland polyps will occur in the majority of patients.