A man in his 70's was admitted to our hospital for treatment of a huge hepatocellular carcinoma (HCC) by transcatheter hepatic arterial embolization (TAE). After treatment, anuria occurred, and laboratory examinations revealed a diagnosis of tumor lysis syndrome (TLS). He underwent conservative therapy including hemodialysis, resulting in complete remission of TLS. On the other hand, poor hepatic functional reserve was seen temporarily. After conservative therapy, biochemical markers returned dramatically. TLS is a group of metabolic complications in cancer therapy. It may occur in highly sensitive tumors, resulting from a rapid release of cytoplasmic degradation products of malignant cells. Generally it is rare in the treatment of solid tumors. In the case of TAE for huge HCC, we should keep the possibility of TLS in mind.