OBJECTIVE To study effectiveness of preoperative portal vein embolization before extensive hepatic resection in patients with primary or secondary liver malignancies. METHODS Between December 1997 and May 2003, right portal vein embolization was performed in 24 patients. The indication to the procedure was a small amount (< 30%) of the future remnant liver. Ultrasound-guided percutaneous transhepatic puncture of the portal vein and embolization of its right lobar branch with Lipiodol, ethanol, gelatin sponge and/or steel coils were used. RESULTS There were no complications of the procedure. In 19-56 (mean, 30) days, CT or MRI showed significant increase of the future remnant liver volume from 25% to 35% of the whole liver; the mean increase was 40%. Laparotomy was performed in 15 patients. Right, extended right hepatectomy, and repeated resection were performed in 7, 6, and 1 patient respectively, while one patient underwent only exploration because of tumor progression. Of 14 resected patients, 11 showed no postoperative liver failure. The latter was medically cured in two of three remaining patients, while one patient (future remnant liver < 30% even after the embolization) died from liver failure in 20 days after the surgery. Hepatic resection is planning in 4 of 9 non-operated patients. The 5 patients were not operated because of tumor progression. CONCLUSIONS Right portal vein embolization is a safe and technically simple procedure that decreases the risk of postoperative hepatic failure after major liver resection.