ABSTRACT:The objective of the study was to evaluate the effect of time of gestation on fatty acid transporter mRNA expression in maternal and fetal bovine placenta. Placentas from twelve cows at different thirds of gestation (n=4 per third) were sampled at slaughter to measure FATP-1, FATP-4, FABP-1 mRNA concentration in maternal (caruncles) and fetal (cotyledons) side. Once the placenta was removed, 1cm 2 was dissected and, divided into caruncles and cotyledons, stored in sterile tubes, dropped into liquid nitrogen and kept at -80° C until rtPCR analysis. Data were analyzed as a complete randomized design with a 3 x 2 factorial arrangement, using the mixed procedure (SAS 9.3) with repeated measurements on space. Time of gestation, side of the placenta and their interaction were fixed factors, whereas animal was a random factor. There was a time by treatment interaction (P < 0.01) on FATP-1 mRNA expression due to a greater mRNA expression in cotyledons on the first third of gestation as compared with the concentration in caruncles. On the second and third stages of gestation, the mRNA concentration in cotyledons decreased, reaching a similar concentration to that observed in caruncles. Fatty acid transport protein -4 and FABP-1 mRNA concentration were not different (P >0.1). We conclude that FATP-1 might play an important role in fatty acid transport during early fetal development.