The aim is to obtain normal newborn umbilical cord diameters for use it in the evaluation of congenital umbilical hernia.The umbilical cord diameter (UCD) at the abdominal wall, maternal age, birth weight, gestational age at birth, birth height, head, chest and abdominal circumferences, and the time of measurement after birth was noted.Mean ± standard deviation and median (minimum-maximum) values of the UCD were 9.9 ± 1.9 mm, 10.0 (5-16 mm), respectively. There was a significance for a positive low correlation between birth height and UCD (p = .039, r = .143). No other birth parameter had a significant correlation with UCD. The gender of the newborn (p = .95) and the type of delivery (p = .056) did not affect UCD.These data may be used in determining the normality of UCD, which could be helpful in the evaluation of umbilical hernias.