Ghrelin and adiponectin have been found in breast milk and are considered to take part in the regulation of growth and energy metabolism of infants. Our aims were to determine ghrelin and adiponectin levels in breast milk and serum samples of mothers and their infants, and to investigate the relationship between their levels and anthropometry of newborn infants during early postnatal life. Total and active ghrelin and adiponectin levels were studied in breast milk, and the serum samples of 25 healthy lactating women and their healthy fullterm infants were taken at the 1st and 4th months of life. Anthropometric measurements of infants were also performed during the study period. Breast milk and infant serum active ghrelin levels were found to be significantly increased at the 4th month of life compared with 1st month levels (p < 0.05). Maternal serum total ghrelin and infant serum adiponectin levels were found to be significantly reduced at the 4th month of life (p < 0.05). Breast milk active ghrelin levels were higher than the infant and maternal serum active ghrelin at the 1st and 4th months (p < 0.05). There was a negative significant correlation between the level of infant serum active ghrelin levels and BMI of infants at the 1st month. A positive significant correlation was found between the level of 1st month infant serum adiponectin levels and weight gain of infants during the study period. Fourth month infant serum adiponectin were also positively correlated with weight and BMI of infants at the 4th month and the weight gain during study period. There was a positive significant correlation between the level of 4th month breast milk active ghrelin and weight gain of infants during the study period. Ghrelin and adiponectin are involved in postnatal growth of infants. Ghrelin in breast milk also seems to be related to the growth of infants during early postnatal life. The sources of these peptides in breast milk are probably both maternal serum and breast tissue itself.