This study was to evaluate the clinical effects of percutaneous balloon angioplasty of Budd-Chiari syndrome (BCS) caused by inferior vena cava (IVC) obstruction. Between 1993 and 1999, 28 men and 14 women with mean age of 44+/-12 years underwent percutaneous balloon angioplasty for primary BCS. Color Doppler ultrasound and venography showed membranous and segmental obstruction of IVC in 29 and 13 patients, respectively. Fourteen patients also had left- and/or mid-hepatic vein obstruction. Angioplasty of IVC was successful in 41 patients (97.6%), resulting in a reduction of pressure gradient between IVC and the right atrium from 15.0+/-2.5 to 5.5+/-0.8 mmHg (P<0.01). A stent was placed in the site of obstruction in the patient with unsuccessful balloon angioplasty. Patients with successful angioplasty or stent placement had significant improvement in clinical symptoms indicated by a reduction in hepatomegaly and the degree of ascites. No specific attempt was made to treat the occluded left- and/or mid-hepatic vein due to the presence of potent right hepatic vein. Over the follow-up period of 32+/-12 months, restenosis of IVC occurred in only one patient (2.4%), which was redilated successfully. Percutaneous balloon angioplasty is a safe and effective therapy for Budd-Chiari syndrome caused by IVC obstruction, therefore should be the first choice of treatment for this condition.