With the rapid increase in the elderly population in Japan and the continued advances in perioperative management and operative techniques, more surgical procedures will be performed in the geriatric patients. The loss of reserve capacity and associated disease in the elderly patients may lead to an inappropriate response to surgical stress, resulting in high morbidity and mortality. Therefore, the identification of surgical risk is imperative in the surgical care of aged patients. The risk factors in the aged include malnutrition, anemia, cerebrovascular disease, hepatic disorders and immunosuppressive therapy. This review focuses on the risk factors and simple method to estimate the surgical risk in aged patients undergoing gastrointestinal cancer surgery.