Exclusively extrahepatic arterial perfusion to previously untreated, early-stage, hepatocellular carcinoma (HCC) is uncommon. We present a case of right superior adrenal artery completely supplying a subcapsular HCC in a 68-year-old male. The extrahepatic arterial territory targeted excluded structures potentially vulnerable to radiation, which allowed safe ablative Y-90 radioembolization that achieved complete pathological necrosis.