To investigate the efficacy of endoluminal ultrasound system (EUS) as a surrogate for high frequency transvaginal ultrasonography and as an optional baseline study in determining parametrial and stromal invasion of early stage cervical cancer, 52 women suspected of cervical cancer underwent EUS. A 12 MHz endoscopic probe was employed to radially scan the cervix for possible lesions suspected to be invasive cancer during a period of 6 months from Feb. I to July 1. 1995. Patients also underwent magnetic resonance imaging (MRI) and/or computerized tomography (CT) as a routine mode of baseline study, and were clinically staged by 3 independent physicians specializing in Obstetrics and Gynecology at the Department of Obstetrics and Gynecology, School of Medicine, Ajou University, Suwon, Korea. Thirty one patients subsequently received surgery appropriate for the stage of the disease and the final pathology findings were compared with the results of clinical staging, EUS, MRI/CT by regression analysis. The results showed that there was statistically significant correlation between MRI/CT and pathology (r=0.660, p<0.02), between EUS and pathology (r=0.803, p<0.01), and between clinical staging and pathology (r=0.825, p<0.01). It is concluded that there was significant statistical correlation between EUS, MRI/CT, clinical staging and pathology, but the question remained as to the statistical superiority of EUS over MRI/CT with regard to parametrial invasion and stromal invasion depth assessment. Finally, EUS is useful as an alternative optional diagnostic tool in the baseline study of cervical cancer.