Patients with peritoneal surface malignancy from gastrointestinal (GI) cancers almost uniformly succumb to advanced locoregional disease in the form of intractable ascites, malignant visceral obstruction and cancer cachexia. The natural history of peritoneal carcinomatosis from GI malignancies is inexorably lethal with median overall survival of approximately 5 months 7, as patients with disease confined to the peritoneum remain at increased risk of synchronous occult hematogenous metastases. While systemic therapy improves outcome in patients with hematogenous disease spread, improvements are needed in the control of peritoneal surface malignancy, which is known to be relatively resistant to systemic agents owing principally to the presence of a peritoneal-plasma partition. Moreover, the results of surgical resection alone for peritoneal dissemination of GI cancer have been disappointing given the difficulty in clearing surgically all microscopic disease foci. The infusion of chemotherapy into the peritoneal cavity provides distinct pharmacokinetic advantages. The addition of hyperthermia potentiates the effect of intra-peritoneal chemotherapy through anti-tumor synergism, without systemic drug absorption.