Immunodiagnostic screening may improve the survival of ovarian carcinoma by earlier detection and follow-up during treatment. Presently, several ovarian cancer-associated antigens are being utilized to monitor treatment response; a specific and precise test for screening is not currently available. The present study was designed to investigate the presence and clinical significance of circulating immune complexes (IC) in patients with ovarian carcinoma using a polyethylene glycol (PEG) assay. If this assay were to prove clinically useful in patients with ovarian carcinoma, its potential as a screening test would then be evaluated. Serum was obtained from 38 patients with advanced ovarian carcinoma preoperatively, postoperatively, and prior to the administration of a combination chemotherapy regimen containing cisplatin. Five patients had values greater than or equal to 0.10. This test identified only 12.5% of the patients with active disease. Serial sampling failed to reveal any correlation with disease status. Our experience does not support the usefulness of IC levels in studying or treating patients with ovarian carcinoma.