When performed based on cytology, histological accuracy of the laser cone specimen improved with the more severe cytology. The incidence of adenocarcinoma in situ is 1.0%. With and without residual disease, the rate of abnormal cytology after laser excision cone are 0.6% and 1.6% respectively. There is good correlation between colposcopic biopsy and cone specimen in the more severe lesions. Out of 139 cases of incomplete excision, only 3 cases had abnormal cytology at follow-up. The complication rates are very low.