The purpose of this article is to review the current status and future perspectives of antibody therapy against cancer. Eight antibody drugs against cancer are now commercially and clinically available for treatment of cancer in the United States and two of them are also available in Japan. Current data suggest that antibodies or their genes against cancer can be used in order to increase the tumor specificity of various new immunotherapeutic or gene therapeutic approaches against cancer, thereby enhancing the tumoricidal effect of each treatment while reducing the side effects.