The relationship between esophageal varices and the azygos vein, which is generally considered to drain the major part of the variceal blood flow, was evaluated by percutaneous transhepatic cineportography in 35 patients with portal hypertension. We classified the patients into three groups. Those patients in whom most of the variceal blood drained into the azygos vein were designated the azygos-type group (n = 18). Those in whom most of the blood flowed into the brachiocephalic venous system were defined as the cervical-type group (n = 5), and those in whom the varices were drained by both the azygos vein and the brachiocephalic venous system were called the combined-type group (n = 12). Highly developed esophageal varices were recognized endoscopically in all patients in the combined-type and cervical-type groups, whereas some of the patients in the azygos-type group had less well-developed varices. In the azygos-type group, a tendency for the varices to be more severe as their drainage into the azygos vein became more cephalad was noted. Evaluation of the drainage of esophageal varices was considered useful not only for obtaining full comprehension of the significance of the azygos vein but also for assessing the suitability for sclerotherapy. Percutaneous transhepatic cineportography was useful for this purpose because it enables visualization of even the most minute amounts of blood flow.