This project was designed to determine if the presence of fibrin degradation products (FDP) in the blood are of value in the prcoperativc evaluation of patients with pelvic masses. This study comprised 120 consecutive patients who were evaluated for a diagnosis of pelvic mass, ovarian cyst, or ovarian carcinoma. A blood sample was drawn from each patient and fibrin degradation products were determined utilizing the Thrombo-Wellcotest. Platelet counts and partial thromboplastin time (PTT) were also determined on each patient. Ovarian carcinoma was present in 17 (14.2%) of the patients. The FDP was found in the serum of 16 (94.1%) of the patients with ovarian carcinoma. One (5.9%) of 17 patients with ovarian carcinoma had a negative FDP (<10 mg/ml). Eleven of the 120 patients (9.2%) had a positive FDP with no demonstrable etiology. A sample of fluid was obtained from two cystic ovarian carcinomas and when analyzed for FDP both samples were strongly positive.