Aim: To determine the number and prevalence of third- and fourth-grade perineal tears with restrictive use of episiotomy, and the prevalence of obstetric anal sphincter injuries (OASIS) according to parity, mode of labor termination, delivery duration, epidural analgesia, obstetric team experience, and neonatal birth weight and head circumference. Subjects and Methods: This retrospective clinical study included 51 women diagnosed with OASIS, having delivered their newborns at Department of Gynecology and Obstetrics, Sveti Duh University Hospital from January 1, 2010 until December 31, 2014. Results: Out of 12858 vaginal deliveries, episiotomy was not used in 77% (n=9887), whereas it was used in 23% (n=2971) of women. The overall prevalence of OASIS during the study period was 0.4%, with 0.7% for mediolateral episiotomy versus 0.3% in women without episiotomy (p<0.05). Statistically signifi cant differences between primiparae and multiparae were recorded for the prevalence of OASIS (68.7% vs. 31.3%) and delivery duration >10 hours (p<0.05). Risk factors for OASIS were present in 33% of women and included fetal head malrotation, shoulder dystocia, and OASIS in previous delivery. There was no statistically signifi cant difference in the prevalence of OASIS according to birth weight <4000 g (78.4%) versus >4000 g (21.6%), maternal body mass index, and second stage of labor >1 hour (43.6%) versus <1 hour (56.4%) (p>0.05 both). Conclusion: Primiparity, delivery duration >10 hours, and use of episiotomy were identifi ed as risk factors for OASIS. Other obstetric risk factors for OASIS were present in one-third of OASIS cases. The prevalence of third- and fourth-degree perineal tears can be reduced with restrictive use of episiotomy and manual perineal protection.