Therapeutic intervention in a course of illness, while producing the desired result, also may have some adverse long-term effects on the patient. Second malignancies are one of the known complications of therapy. The treatments of gynecologic cancers by surgery, irradiation and chemotherapy have been associated with subsequent neoplasms. Care must be exercised in associating previous therapy and a subsequent malignancy. "Naturally" occurring second cancers must be separated from those which are iatrogenic. Associations in the literature have been made involving malignancies as a sequelae of prior gynecologic therapy. The use of normal skin from the thigh to fabricate an artificial vagina has resulted in more squamous cell carcinomas than expected. Alkylating agents used in the treatment of ovarian cancer and other diseases have been shown to lead to an increased risk of leukemia. Irradiation therapy, however, has not yet been shown to be related to leukemia in cervical cancer patients. The incidence of lymphoma and uterine, urinary bladder and colon carcinomas has been associated with prior irradiation for gynecologic disease. The literature regarding the therapeutically induced risk factors in gynecologic therapy is reviewed and areas of our knowledge that require more investigation are identified.