Estrogen and progesterone receptor levels (ER and PR) were measured in 21 specimens of cervical carcinoma and in 17 normal cervix by monoclonal enzyme immunoassay (ER-EIA and PR-EIA). In normal cervix, 88.2% of specimens were ER-positive (more than 15 fmol/mg protein), 74.5% were PR-positive (more than 15 fmol/mg protein) and 74.5% were both ER and PR-positive. In cervical cancer, 66.7% of malignancies 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 level and in ratio of PR/ER was noted (P < 0.05, P < 0.01).