Renal cell carcinoma (RCC) is considered to be an immunogenic cancer. RCC is refractory to chemotherapy and radiation. Immunotherapy including interferon (IFN)-alpha, gamma and interleukin-2 are the treatment of choice for metastatic RCC. IFN-alpha is most widely used in Japan. The response rate of IFN-alpha is 10-20 %. Lung lesions and lymphnodes are the usual effective sites. The survival benefit of IFN-alpha in patients with metastatic RCC has been shown in prospective randomized studies. Nephrectomy is recommended before interferon therapy if the patients have good performance status. Adjuvant interferon therapy failed to show any survival benefit after curative excision of primary RCC. The place of IFN-alpha is going to be changed due to the recent use of molecular targeting drugs.