Melamine contamination is a recent public health problem emerging globally. Present study aimed to detect the rate of melamine presence in human milk in a cohort study and to evaluate any possible differences in maternal-infant pair characteristics such as breastfeeding status, crying and sleep problems of infants, maternal postpartum depression, maternal-infant bonding, infant and maternal anthropometry, and maternal complete blood count caused by the melamine exposure. Mothers of infants born in Sanliurfa were invited to participate in 'Urfa Child Cohort Survey'. Overall, two breast milk samples were taken between 5 days and 15 days postpartum and between 4 weeks and 10 weeks. Randox Food's InfiniPlex array was used to analyse the presence of melamine. Melamine was detected in 32.2% and 24.4% of the first and the second milk samples; 16.7% of mothers had two positive samples. z Scores for birth weight and z scores for height for age were detected to be significantly lower in cases with two positive samples compared to cases with negative samples. Mean maternal white blood cells counts were found to be lower in cases with repeated melamine contact. Melamine might have a detrimental effect on birth weight, infant height and maternal blood count. Further studies should be done to detect environmental contamination in different regions and countries.