<p class="abstract"><strong>Background:</strong> Neonatal jaundice is one of the most common problems in the neonatal period. Eosinophilia is common in preterm and term newborns, and it is considered when the absolute count of eosinophil is ≥500 cell/mm<sup>3</sup>. It is thought that there was some relationship between hyperbilirubinemia and increasing of blood eosinophil count in newborns hospitalized by jaundice. The aim of this study was to determine the prognostic value of peripheral blood eosinophil count on first day of infancy in the incidence of neonatal hyperbilirubinemia.</p><p class="abstract"><strong>Methods:</strong> 150 newborns with gestational ages of 35-40 weeks, born in Ardabil city hospital, were engaged in this study. After obtaining the parents' consent, getting patients biography and their physical examination, we got a blood sample from umbilical cord of newborns to measure differential count of white blood cells. The neonates were observed up to 28 day followed. Then, second blood test conducted for the purpose of measuring serum level of bilirubin. Data were analyzed by statistical methods in SPSS version 19. </p><p class="abstract"><strong>Results:</strong> Various group of age, sex, blood type and gestational age showed no significant difference in their eosinophil rate. Total serum bilirubin doesn't had a significant relationship with gestational age, sex, type of delivery and major or minor blood groups of neonates.</p><p class="abstract"><strong>Conclusions:</strong> Results showed that there was no significant relationship between the amount of eosinophil in newborn umbilical cord and total serum bilirubin. So, we could say that newborns eosinophil count isn’t a good criteria for predicating the appearance of neonate hyperbilirubinemia.</p>