Duodenal varices are a rare occurrence, and the diagnosis and control of related bleeding is problematic. The vascular anatomy of duodenal varices in four patients was examined angiographically. The incidence of these varices was 0.4% in the patients with portal hypertension seen in our clinics from 1982 to 1991. The transparent specimen obtained at autopsy and treated with methyl salicylate and portographies in the remaining three patients revealed that the duodenal varix consisted of a single vessel with afferent and efferent vessels, forming a portasystemic shunt in the retroperitoneum. The varix transversed the duodenum and was present in the submucosal layer of the posterior wall. The afferent vessel was the superior or inferior pancreaticoduodenal vein originating in the portal vein trunk or superior mesenteric vein. The efferent vein drained into the inferior vena cava. In view of these observations, devascularization or percutaneous transhepatic obliteration of the varix would be our first choice of treatment for patients with duodenal varices.