Estrogen and progesterone receptors (ER, PR) were measured in 21 specimens of cervical cancer and in 17 specimens of normal cervix by monoclonal enzyme immunoassay (EIA). In normal cervix, 88.2% of specimens were ER-positive ( > 15 fmol/mg protein), 74.5% were PR-positive ( > 15 fmol/mg protein) and 74.5% were both ER- and PR-positive. In cervical cancer, 66.7% were ER-positive, 42.9% were PR-positive and 38.1% were both ER- and PR- positive. There was no significant difference in ER status between the normal cervix and cervical cancer (P > 0.05), but PR status and levels in normal cervix were significantly higher than those in cervical carcinoma (P < 0.05). ER levels in squamous cell carcinoma was not correlated to the tumor stage, histologic grade and menopausal status. PR levels in premenopausal patients with squamous cell carcinoma were significantly higher than those in postmenopausal patients (P < 0.01). Adenocarcinoma of the cervix contained significantly more ER and PR than squamous cell carcinoma (P < 0.01, P < 0.05). In addition, serum E2 level was also assayed in 21 patients with cervical cancer. There was significant difference in E2 levels between the premenopausal and postmenopausal patients (P < 0.01). Patients were stratified according to E2 levels, a significant difference in PR levels and in the ratio of PR/ER was noted (P < 0.05, P < 0.01).