This study evaluated outcomes of laser vaporization of the cervix for women with cervical intraepithelial neoplasia (CIN)-3. We retrospectively reviewed 161 consecutive patients with CIN3 who were treated with cervical laser vaporization between January 2008 and December 2012. At each follow-up visit, histologically confirmed CIN2, CIN3 and invasive carcinoma were defined as treatment failures, as were high-grade squamous intraepithelial lesion (HSIL) or atypical squamous cells that cannot exclude HSIL with subsequent treatment or lost to follow-up. Primary endpoints included long-term follow-up (at least 5 years of regular hospital visits) and treatment failure rate. Treatment failure rates were estimated by the Kaplan-Meier method. Patients' median age was 31 years old. Median follow-up period was 67 months (interquartile range: 52-74 months). Over 5 years, 70.8% continued their follow-up visits, but significantly more patients aged ≥35 years did so (86.4%) than did those aged ≤34 years (61.8%, P = 0.0009). Treatment failure was observed in 14 (8.7%) patients, 1 of whom progressed to invasive cancer (0.6%). Cumulative treatment failure rates were 1-year: 5.1%, 2-year: 6.4% and 5-year: 9.5%. Among patients who suffered treatment failures, 57.1% initial failures occurred within the first year and 71.4% within the first 2 years. Long-term oncologic outcomes of cervical vaporization in CIN3 remain at a suboptimal level. The importance of a minimum of 5 years of regular hospital visits should be emphasized to patients with CIN3 who are candidates for cervical laser vaporization, especially those aged ≤34 years.