The purpose of our study was to examine the concordance among colposcopy, cytology, and histology in the diagnoses of intraepithelial lesions of the uterine cervix. We compared the results of Pap tests, biopsies, and colposcopy in 190 patients, who had histologically proven CIN and/or HPV infection, using histology as "the gold standard". The chi 2 (chi square) test was used for the statistics analysis. The sensitivity of cytology for the detection of CIN was 70%, and was lower for LGL (low grade lesions) than for HGL (high grade lesions): 61.2% versus 88.5%, respectively (p < 0.0001). We obtained a high rate of false negative smears (30%), with a relatively high rate of inadequate samples (59.6%). The sensitivity of colposcopy was 92%. Our results suggest that the Pap test alone is no longer sufficient for the screening of precancerous lesions of the cervix, and colposcopy is compulsory each time the smear is inadequate or altered.