During the past decade, intraperitoneal therapy of ovarian cancer has evolved from a pharmacologic model into an established treatment technique for women with this malignancy. Approximately 40% of patients with small-volume residual ovarian cancer (microscopic disease or macroscopic tumor, < or = 0.5 cm in maximum tumor diameter), after an objective response to initial organoplatinum-based systemic chemotherapy, may have a surgically documented complete response to platinum-based intraperitoneal chemotherapy. Patients who have not responded to systemic platinum administration rarely will respond to the drug given intraperitoneally, despite the presence of only small-volume residual disease when this regional treatment strategy is used. Other agents with antineoplastic activity after intraperitoneal administration in women with ovarian cancer include mitoxantrone, taxol, alpha-interferon and gamma-interferon, and interleukin-2. Although intraperitoneal therapy currently is being examined as a component of the initial chemotherapeutic program for patients with ovarian cancer, a precise role for regional drug delivery in this clinical setting remains to be defined.