The concurrent clinical events of pregnancy and untreated Cushing's syndrome are rare, with fewer than 100 affected patients documented in the medical literature since 1953. When these conditions coexist, maternal and perinatal morbidity and mortality rates are substantial. Therapy to relieve hypercortisolism has been instituted in one-third of reported pregnancies. Such therapy includes pituitary and adrenal surgery, chemotherapy, and pituitary irradiation. The impact of definitive therapy on maternal outcome is unclear, but perinatal outcome appears to be little affected by directed therapy.