Abstract Spontaneous regression of hepatocellular carcinoma (HCC) is a rare phenomenon. This case of a 65-year-old Korean man with HCC and metastatic frontal bone mass that regressed after radiotherapy for frontal bone mass without any other therapeutic modalities is described. The clinical diagnosis of HCC was made because of the presence of a liver mass on abdominal computed tomography (CT) scan, high serum α-fetoprotein value and tissue diagnosis on frontal bone biopsy. The patient refused any other recommended treatments, but accepted the radiation therapy due to a painful frontal bone mass, and ingested mushroom called Phellinus linteus for one and a half years. Ten months after radiation therapy, he experienced a reduction in size of the frontal bone mass and improvement of lesions in the liver, sternum and ribs. The patient is alive and in good condition without any symptoms or tumor aggravation in August 2002. It was concluded that a rare case of spontaneous regression of HCC had occurred.