OBJECTIVE The purpose of this study was to evaluate the efficacy of transcatheter arterial chemoembolization (TACE) through collaterals after hepatic artery occlusion or severe stenosis in patients with hepatocellular carcinoma (HCC). METHODS During the past three and one-half years, 19 of 167 patients with HCC showed hepatic artery occlusion or severe stenosis after repeated TACE, and 17 patients underwent TACE through collateral arteries. Types of collaterals, results, and effects of TACE through collaterals were evaluated. RESULTS Common collaterals were periportal collateral, intrahepatic anastomosis, and right inferior phrenic artery. TACE was successfully carried out through all detected collaterals in 40 of 49 TACE trials (82%). In eight of 49 TACE trials (16%), TACE through collaterals was partially carried out. The cumulative survival rates at the end of the first, second, third, forth and fifth year were 100%, 79%, 79%, 59% and 59%, respectively. CONCLUSIONS TACE through collateral arteries was able to be performed in most cases and will be an effective treatment to control HCC.