Carcinoembryonic antigen (CEA) levels have been measured in cervico-vaginal washout fluid using the direct CEA Roche radioimmunoassay. Raised CEA levels were found associated with cervical intra-epithelial neoplasia and invasive carcinoma (85% above 300 ng/ml) compared with benign cervical lesions (29% above 300 ng/ml), suggesting that estimation of local CEA levels might be a useful adjunct to cytology and biopsy in the investigation of cervical neoplasia.