Introduction: There is a high rate of deliveries in adolescents in Mexico. This age group is vulnerable to obstetric complications, including lacerations of the anal sphincter.Objective: To determine the prevalence of third and fourth degree perineal tears in adolescents during childbirth, and to evaluate risk factors in comparison with deliveries with lacerations of adult women.Methods: All obstetric care episodes were reviewed from a public tertiary hospital data in Monterrey, Mexico in 2014. Age, primiparity, delivery instrumentation, episiotomy, body mass index, product weight and tear´s degree were documented at the deliveries with tears of third and fourth degree.Results: The prevalence of third and fourth degree tears of 2.0% was found in the general population, being adolescents the most affected with 2.5%. The unadjusted odds ratio of high-grade tears in adolescent females at delivery, compared to adult females, was 1.36 (95% CI = 0.99-1.86, p= 0.05). No difference was found when comparing risk factors among high-grade tear deliveries in adolescents versus adults.Conclusions: A higher prevalence than previous reported for high grade tears during delivery was found. The data suggest adolescence as a risk factor for high-grade tears during delivery.