The aim of this study was to evaluate the diagnostic accuracy of endocervicoscopy as a preoperative examination to improve the outcome of the excisional treatment (LEEP) of high-grade cervical preneoplastic lesions.Patients with histologic diagnosis of CIN II-CIN III undergoing LEEP divided in two groups: in group A (85 women) a preoperative endocervicoscopy was performed, in group B (85 women) no additional examination was performed before LEEP. The size of the surgical specimen (H, D, W) and the margins of the lesion were evaluated.Seventy-four women in group A and 80 in group B completed the follow-up. group A showed significant correlation between colposcopic examination and endocervicoscopic examination (P=0.001, k=0.30) and between endocervicoscopic and definitive histological examination (P0.05, k=0.16). The depth of the operative sample was significantly lower (P0.0001) in group A (0.91±0.4) than in group B (1.58±0.2), group A showed fewer patients B with positive endocervical margins than group B (3 vs. 17, P002). Colposcopic, cytological and virological follow-up did not show significant differences between the two groups.Endocervicoscopy as preoperative tool for excisional treatment of cervical lesions showed high diagnostic effectiveness and allows to perform a conservative surgery.