To evaluate results of three phase 3 clinical trials of quadrivalent HPV 6/11/16/18 vaccination of young Asia-Pacific women.A total of 814 women from the Asia-Pacific region (aged 16 to 26 years) received vaccine or placebo in 1 of 3 protocols. Descriptive analyses focused on the efficacy, safety, and immunogenicity of the vaccine and the natural history of HPV disease.Vaccine efficacy against disease caused by HPV types 6, 11, 16, or 18 was 100% for cervical intraepithelial neoplasia (0 vs 12 cases; 95% confidence interval [CI], 63.1%–100%) and 100% for vulvar and vaginal intraepithelial neoplasia or condylomata accuminata (0 vs 5 cases; 95% CI, −11.8% to 100%). The vaccination was highly immunogenic. Vaccine recipients experienced a significantly higher injection site adverse event rate (P=0.002). Compared with other world regions, lower rates of smoking and baseline positivity to 14 HPV types (including the vaccine types) were observed among Asia-Pacific participants.Prophylactic quadrivalent HPV 6/11/16/18 vaccination of young Asia-Pacific women demonstrated high efficacy, safety, and tolerability. Together with an observed low baseline HPV positivity rate, the Asia-pacific population is potentially an important cohort to benefit from vaccination.