Objective: To evaluate vaginal birth safety by comparing the results of cesarean birth in twin pregnancies with the first twin in vertex presentation. Materials and methods: A retrospective cohort study of vertex-presenting twin pregnancies between 32 weeks 0 days and 38 weeks 6 days of gestation was conducted at our hospital from January 2013 to December 2015. The study population was divided according to the mode of birth. The primary outcome was early neonatal mortality, and secondary outcomes related to maternal and perinatal clinical characteristics were analysed between the groups. Results: Of 45,166 births, 1.92% (n = 869) were twin pregnancies. Of the 295 pregnancies meeting the study criteria, 30.16% (n = 89) were in the vaginal birth group, while the remaining 69.84% (n = 206) were in the cesarean birth group. In the vaginal birth group, all the first twins were delivered via vaginal birth, while among the second twins, 82.03% (n = 73) were delivered via vaginal birth, and the remaining 17.97% (n = 16) were delivered via cesarean birth. In the vaginal birth group, the early neonatal mortality rate was 2.24% (n = 2), and it was 0.97% (n = 2) in the cesarean birth group. All of the deaths occurred in pregnancies under 37 weeks of gestation. Conclusion: The neonatal outcomes between the vaginal birth and cesarean birth groups were similar in term pregnancies with the first in twin vertex presentation, whereas adverse neonatal outcomes were increased in the vaginal birth group in preterm second twin pregnancies.