Stage IIIC, grade 1 papillary serous adenocarcinoma of the ovary was diagnosed in a 28-year-old renal transplant recipient. She had been treated with the immunosuppressive agents azathioprine and methylprednisolone for 7 years prior to the discovery of the ovarian cancer. Surgical excision of the tumor was suboptimal due to involvement of the allograft; however, the patient achieved a complete clinical response after eight courses of cisplatin and cyclophosphamide. Since multiagent immunosuppressant therapy may have contributed to the development of the ovarian carcinoma, the intensity of immunosuppression was decreased by discontinuing the azathioprine as soon as the diagnosis of ovarian cancer was made. The methylprednisolone, however, was continued to decrease the possibility of organ rejection. After completion of chemotherapy, the patient was started on a daily regimen of low-dose oral cyclophosphamide as an immunosuppressant. Four months following the completion of cytotoxic therapy, she developed clinically evident disease in the pelvis. Subsequent salvage therapy with carboplatin failed. The patient died from progressive disease 26 months after initial diagnosis. She never developed evidence of renal rejection. Combined modality cancer therapy, preservation of allograft function, and modification of immunosuppressant therapy are important goals in the renal transplant patient with advanced ovarian carcinoma.