Hepatic arterial collaterals can be seen following ligation of the hepatic artery by chemoembolization. We retrospectively analysed the arterial collaterals associated with hepatoma and classified them on angiograms by various location, size, pattern fo hepatoma, and invasion of the portal vein. A total of 171 patients with primary hepatoma were included in this study and arterial collaterals were seen in 101 patients. The classification of the collaterals was as artery origin in 16 cases, left gastric artery origin in 14 cases, right paracolic gutter route in 5 cases, intercostal artery origin in 1 case and adrenal artery origin in 1 case. Our results suggest that arterial collaterals by primary hepatoma were a frequent finding and examination of them was helpful for effective treatment of hepatoma especially for chemotherapy or selective embolization.