General Background: Perineal rupture is a common condition during vaginal delivery that may cause hemorrhage, infection, and postpartum discomfort. Specific Background: Prenatal yoga is described as a pregnancy exercise involving physical movement, breathing regulation, relaxation, and pelvic muscle strengthening to support preparation for childbirth and reduce perineal rupture. Knowledge Gap: The relationship between regular prenatal yoga participation and perineal rupture occurrence among primiparous women undergoing vaginal delivery requires further assessment. Aims: This study aimed to analyze the relationship between prenatal yoga and the incidence of perineal rupture during vaginal delivery. Results: This quantitative study used a retrospective cohort design involving 36 primiparous postpartum women selected through purposive sampling. Data were obtained through interviews regarding regular prenatal yoga participation and medical-record observations of perineal rupture, then analyzed using Fisher’s Exact Test. Most respondents practiced prenatal yoga regularly (66.7%), while 58.3% did not experience perineal rupture. Among regular participants, 87.5% experienced no rupture, compared with 0% among those who practiced irregularly. The statistical test showed a significant relationship between prenatal yoga and perineal rupture occurrence (p=0.000). Novelty: The study presents empirical findings on regular prenatal yoga participation and perineal rupture among primiparous women delivering vaginally in Sidoarjo. Implications: Prenatal yoga may be considered as a promotive and preventive component of antenatal care to support efforts to reduce perineal rupture during vaginal delivery. Key Findings Highlights Regular prenatal yoga participation was reported by 66.7% of respondents. A total of 58.3% of respondents experienced no perineal rupture. A significant relationship was identified between prenatal yoga participation and perineal rupture occurrence (p=0.000). Keywords : Prenatal Yoga, Perineal Rupture, Vaginal Delivery, Primiparous Women, Antenatal Care