Recent advances in gynecologic tumor biology are discussed with an emphasis on the development of biologic therapy. Emerging knowledge regarding growth factors, regulatory cytokines, and cellular receptors offers new insight regarding tumor biology and the interaction of tumors with the host peritoneal cavity and immune system. Efforts to target ovarian cancer with antibodies directed against tumor-associated antigens have begun to take advantage of molecular engineering techniques and have also explored an expanded panel of radionuclides with improved conjugation technology. It is hoped that these efforts will translate into successful strategies to improve the long-term survival of patients in conjunction with conventional chemotherapy.