Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 49 8 2011 08 15 543 546 EN Hamideh Shajari Department of Neonatology, Shariati Hospital, School of Medicine, Tehran University of Medical Science, Tehran, Iran. Neda Rashidiranjbar Department of Neonatology, Shariati Hospital, School of Medicine, Tehran University of Medical Science, Tehran, Iran. Mahmoodreza Ashrafi Department of Neurology, Children’s Medical Center, School of Medicine ,Tehran University of Medical Science ,Tehran, Iran. 2015 09 28 There is limited data in the literature on the normal size of the anterior fontanelle. This crosssectional study was to determine normal values of anterior fontanelle size on the first day of life, using standard methods. Anterior fontanelle size was measured in 400 term and healthy neonates delivered at the Shariati Hospital, Tehran, Iran. Examination included assessment of head circumference, anterior fontanelle size, weight, length. Type of delivery was also recorded. The mean size of anterior fontanelle was 25.34 ± 13.27 mm, and it was established in both genders, 26.70 ± 13.19 mm in boys, and 23.67 ± 13.20mm in girls. A significant difference between the mean anterior fontanelle size in boys and girls was found (P=0.023). There was no significant difference in anterior fontanelle size between the infants born with a normal vaginal delivery and those with cesarean-section (P=0.08). There was found a significant negative correlation between the mean size of anterior fontanelle size with both weight and height (P<0.05). No significant correlation was found between mean size of anterior fontanelle and head circumference or with gestational age of infant (P≥0.05). Our results proved possible to define a references range and centile chart. The method used is simple and accurate and easy used in the routine neonatal examination. https://acta.tums.ac.ir/index.php/acta/article/view/3792 https://acta.tums.ac.ir/index.php/acta/article/download/3792/3767