Balloon-occluded retrograde transvenous obliteration of gastric varices by a microcatheter insertion method was performed in eight patients with large collateral veins or a large gastrorenal shunt. A 3-F microcatheter was selectively inserted into the gastric varices through a 6-F balloon catheter wedged in the left adrenal vein. Selective venography of the gastric varices and injection of the sclerosing agent, a mixture of 10% ethanolamine oleate and iopamidol, through the microcatheter system without occluding the collateral veins was accomplished in one treatment session in all patients. There have been no complications or recurrences of gastric varices in any of the patients during the follow-up period.