Background/Aims: The objective of the study was to evaluate the circulating concentrations of plasma free fatty acids (FFA), fatty acid binding proteins: FABP-1 and FABP-4 in preterm infants depending on different feeding protocol. Methods: A total of 43 premature infants (≤34 weeks) were enrolled in the study, and divided into 3 subgroups: nursed while staying in the department (53%), breast-fed only during the first 24 h (16%), and formulafed from the beginning (31%). The control group consisted of 12 healthy, full-term, breast-fed newborns. Blood samples were collected after delivery and 1 month later. We measured plasma concentrations of FFA, FABP-1, and FABP-4. Results: FFA plasma concentrations were significantly lower in preterm babies when compared to control group (p = 0.003) in the prenatal period. After 1 month, a significant decrease in FFA concentration was noted in all groups of preterm babies independently from feeding protocol. After a month, breast-fed preterm infants and controls had significantly lower FABP-1 levels than preterm formula-fed infants (all p < 0.05), while the highest concentrations of FABP-4 were noted in formula-fed preterm infants when compared to breast-fed preterm infants and the control group (all p < 0.05). Conclusions: Prematurity is connected with disturbances in plasma FFA concentrations. FABP-1, as well as FABP-4, plasma levels in preterm infants depend on feeding protocol.