Physiological jaundice is common in breastfed babies and is attributed to inadequate breastfeeding. However the mechanism underlying its pathogenesis is not clear. Aim: To investigate the possible relationship between neonatal jaundice and levels of interleukin I β in the colostrum of their nursing mothers. Methodology: Blood samples from 60 neonates were drawn for the measurement of total serum bilirubin (TSB) with simultaneous expression of colostrum samples from their mother for measuring Interleukin-1β and full clinical assessment of the pair. Findings: Level of IL1β in breast milk was significantly higher in the group with neonatal jaundice and was positively correlated with TSB levels and mother age at P