Clinical staging is often inaccurate in the evaluation of local extension of cervical carcinoma. In the present study the sensivity of MR imaging in predicting extracervical tumor invasion on the basis of the detection of a thinning of the univolved cervical stromal ring (3 mm or less) was compared to the sensivity achieved by direct visualization of a complete stomal interruption. Fifteen consecutive patients with adenocarcinoma of the uterine cervix (FIGO stage Ib-IIa), were examined with axial and sagittal weighed MR sequences. Pathologic proof after hysterectomy was obtained in all subjects. The sensitivity in predicting extracervical involvement on the basis of the MR Imaging visualization of a thinned stroma was 83%, whereas the sensitivity obtained by detection of a complete stromal interruption was 50%. Among women with a spared cervical stroma of more than 3 mm at MR Imaging, only one had at pathologic examination microscopic metastasis in a parametrial lymphnode, accounting for a negative predictivity value of 87%. The results of our study points out a high concordance between MR Imaging findings and pathologic results, and indicate that the detection of a intact cervical stromal ring exceeding 3 mm at MR imaging is related to a very low risk of extracervical seeding of tumor. On the other side, the detection of a thinned stromal ring is related to a high incidence of parametrial invasion. The information obtained by this imaging technique may therefore be extremely useful in the accurate tailoring of treatment for these patients.