A 55-yr-old woman with Budd-Chiari syndrome was treated by percutaneous transluminal angioplasty with a balloon catheter. Before and after treatment, portal scintigraphy was performed by the administration of [123I]iodoamphetamine per os and per rectum. An enteric capsule was used for the oral administration. Before treatment, the portal shunt index via the superior mesenteric vein was 40.5%; two weeks after treatment, it was 50.2%; and five months after treatment, it was 41.2%. Before treatment, the portal shunt index via the inferior mesenteric vein was 86.0%; two weeks after treatment, it was 87.6%; and five months after treatment, it was 21.8%. The treatment improved the portal circulation through the inferior mesenteric vein only, with little effect on the portal circulation through the superior mesenteric vein.