Spontaneous regression of hepatocellular carcinoma was observed in a 67-year-old Japanese male with liver cirrhosis. Although the patient showed no histological evidence of hepatocellular carcinoma, findings obtained by hepatic angiography, computed tomography and echography strongly indicated that the tumor was a hepatocellular carcinoma. Moreover, the rate of growth of the tumor nodule paralleled an increase in serum alpha-fetoprotein. Following this accelerated increase in serum alpha-fetoprotein a sudden drop was observed with no specific treatment for cancer, and regression of the tumor was also observed. Six months later the serum alpha-fetoprotein level had normalized, and the tumor had disappeared completely. The patients is now alive and doing well more than 70 months after the initial diagnosis of hepatocellular carcinoma.