Biological therapy is currently being investigated in the treatment of a number of malignancies. The hypothesis for the use of this therapeutic modality involves an attempt to stimulate an already existent but perhaps suboptimal immune response to foreign protein, including tumor. Immunologic therapy appears to work best against small-volume disease, as indicated from animal studies. This condition is potentially achievable in advanced ovarian cancer, where surgery is capable of producing multi-log reduction in tumor mass, and thus immunotherapy may be an option in this disease. The attraction of biologic therapy in patients with ovarian cancer is the potential to treat relatively localized but often chemotherapy-resistant disease. In cervical cancer, the rationale for the use of interferon is somewhat different in that this disease may be a manifestation of a virally induced proliferative lesion. Thus, the antiviral properties of interferon are being investigated in both limited and advanced cervical cancer. Both of these hypothesis have pre-clinical data to support them. This paper presents the pre-clinical and clinical work currently available for consideration of future use.