The Zollinger-Ellison syndrome, which is due to the secretion of gastrin from non-beta islet cell tumors of the pancreas, results in gastric hypersecretion and severe peptic ulcer disease. In the 1970s H2 blockers became the mainstay of therapy. More recent evidence indicates that early surgical intervention aimed at tumor extirpation results in improved outcome. The purpose of this paper is to report the case histories of three patients with Zollinger-Ellison syndrome and to review the current literature on management of patients with this syndrome.