Background: Blood pressure (BP) is an important vital sign and indicator of clinical stability. Therefore, the accurate measurement and interpretation of this physiological signal is essential for the optimal management of ill newborns. In this regard, the present study aimed to determine BP values and percentiles in stable newborns in the first weeks of life and evaluate the relevant factors.Methods: This prospective observational study was conducted on 320 term and preterm newborns between 26 and 42 weeks gestational age (GA) within 2015-2017. The exclusion criteria entailed: 1) birth asphyxia,2) preeclampsia, 3) gestational diabetes mellitus (GDM) type I, 4) illicit substance use, and 5) major congenital anomaly. The oscillometric technique was used for BP measurement and systolic and diastolic BPs were analyzed by regression analysis for various percentiles (5th to 95th).Results: The neonates in the current study consisted of 185 (57.8%) males and 135 (42.2%) females with mean (SD) birth weight of 2058.3±582.5grams. Mean (SD) gestational age was reported as 32.95(3.97) weeks. 69.1 % of neonates were delivered via cesarean section. Percentile charts (5th- 95th values) which were developed for systolic (SBP) and diastolic (DBP) demonstrated a steady rise on the respective days that were comparable between different groups. Term neonates were found to have higher BPs, compared to their preterm counterparts on the respective days. Moreover, the neonates who were delivered vaginally had higher mean BP values than neonates delivered via cesarean section.Conclusion: The current study provided normative BP values among neonates, especially in the first two weeks of life. Data presented in this study which include delivery-mode-specific BP percentile curves using an oscillometric method serve as a valuable reference for physicians in the management of newborns in the neonatal unit.