Three hundred thirteen laser cone biopsies were performed for cervical intraepithelial neoplasia (CIN) over a 4-year period. The mean age of the patients was 39.9 years and average cytology follow-up was just under 3 years. Six patients defaulted colposcopic review and were excluded from analysis. Of the 75 cases with CIN extending to the endocervical resection margin, 9 (12%) were found to have residual disease. Only 2 (3.6%) of 56 cases with CIN extending to the ectocervical margin had residual CIN detected. In the 176 cases in which the CIN lesion was excised completely there have been no cases of residual CIN. The overall detection of residual disease was 3.6%. Further surgery in those cases with CIN extending to the resection margin is excessive. These patients should be managed conservatively with regular cytological follow-up.