OBJECTIVES: The aim of this study is to investigate mode of delivery of singleton macrosomic pregnancies over 4000 g in primiparous mothers in one-year period at University Hospital Split. SUBJECTS AND METHODS: Out of total number of births in one-year period from June 1st 2021. till June 1st 2022. we selected 238 primiparous women who gave birth to macrosomic newborns weighing more than 4000 g. Multiple pregnancies and multiparous women were excluded from the study. We devided newborns according to their birth weight into three groups: 4000-4499 g, 4500-4999 g and over 5000 g. The data were collected from the birth protocols of the Department of Gynecology and Obstetrics and from the hospital information system. RESULTS: In the observed period, out of total 238 births of macrosomic newborns among primiparous women, 136 (57%) pregnant women gave birth vaginally, 81 (34%) by emergency and 21 (9%) by elective cesarean section. Emergency and elecive cesarean sections were performed by mothers with a significantly higher body mass index, median 23,8 kg/m2 and 26,3 kg/m2 versus median 22,4 kg/m2 of pregnant women who successfully delivered vaginally (P<0.001). Infants born by emergency and elective caesarean section have a significantly higher median birth weight of 4240 g and 4300 g compared to the those born vaginally (4130g, P<0.001). In the group of newborns with a birth weight of 4000-4499 g, the most successful delivery was vaginal, in the groups of 4500-4999 g and >5000 g, most deliveries were completed by caesarean section (P=0.014). Mothers whose comorbidities were gestational diabetes, preeclampsia and IDDM more often had cesarean section delivery. The use of epidural analgesia and induction of labor did not reduce the frequency of caesarean section. Shoulder dystocia occurred significantly more often in the group of newborns >5000 g (P<0.001). The largest number of manual explorations of the uterus, placenta lysis and vacuum extraction is related to the group of newborns up to 4500g, but without statistically significant difference. Episiotomy was performed significantly more often in the group of newborns up to 4500 g (P=0.012). Primary, secondary inertia, fetal distress and cephalopelvic disproportion were common causes of vaginal delivery conversion to emergency cesarean section. CONCLUSION: Births of macrosomic newborns in primiparous women were more often successfully completed vaginally compared to cesarean section. A greater proportion of mothers with a higher body mass index ended their pregnancy by caesarean section.