Typhlitis is a necrotizing process of the cecum, occurring in neutropenic patients who are usually receiving combined chemotherapy. The atonic cecum is affected because of its poor arterial perfusion, the presence of colonic bacteria, and the milieu of immunosuppression. It is a serious but not inevitably fatal complication of the patient's basic illness. Resection of necrotic bowel is necessary. Because this will usually be done on an emergency basis in a very ill patient with unprepared bowel, a two-stage procedure rather than primary anastomosis is advisable. Surgical results may be better in adult than pediatric patients. The incidence of the problem has probably increased since the advent of aggressive drug therapy of the leukopathic states. Judging from the low number of reported adult cases and the apparent inaccuracy of preoperative diagnosis, there may be inadequate physician awareness of typhlitis.