We present an unusual case of spontaneous regression of hepatocellular carcinoma (HCC). A 77-year-old man with alcoholic liver cirrhosis presented with a 50-mm tumor in the Couinaud's segment 8 (S8) of the liver, a 15-mm tumor in the S8-7 and 10-mm tumors in the other segments (S4, S6). The tumors were diagnosed as HCC by typical imaging findings and elevated serum alpha-fetoprotein (AFP, 1,825.0 ng/ml) and protein induced by vitamin K absence II (PIVKA II, 3,043 mAU/ml). One month later, AFP and PIVKA II decreased to 51.1 ng/ml and 411 mAU/ml, respectively, and the 50-mm tumor in the S8 became small and completely necrotic on angiography and computed tomography arteriography without any treatment. On the other hand, the 15-mm tumor in the S8-7 decreased in size to 10 mm and received blood supply from the right posterior superior arteries (A7). The other 10-mm tumors remained. Ischemia of the tumors due to disruption of the feeding artery (A8) might have induced tumor regression in the present case.