Two experiments were conducted to investigate the effect of L-Carnitine administration on energy metabolism during periparturient period in fat tailed ewes. In Experiment 1, L-Carnitine (I g/50 kg, Treatment 1, n=8) and physiologic saline (Treatment 11; n=8) were administered subcutaneously weekly until lambing for seven or eight weeks. In Experiment 11, L-Carnitine (0.5 g/50 kg, Treatment 1, n=6) and physiologic saline (Treatment 11; n=5) administered subcutaneously twice a week until lambing for at least three weeks. Blood samples were collected during treatments and one week after lambing to determine serum non esterified faty acid (NEFA), beta-hidroxybutiric acid (BHBA), total triglyceride and glucose concentrations. In experiment 1, NEFA concentrations significantly (P<0.01) increased until parturition followed by sudden decrease, and the concentrations were significantly lower (P<0.01) in L-Carnitine group. In Experiment 11, serum NEFA concentrations were significantly (P<0.01) lower at and one week prior to lambing in ewes treated with more than four weeks compared to those treated with four or less than four weeks prepartum. Serum concentrations gradually (P<0.01) increased until parturition followed by sudden decrease in all groups. However, serum NEFA concentrations did not differ in Experiment II. In conclusion, L-Carnitine administration during periparturient period decreased serum NEFA concentrations without any changes in serum BHBA, triglyceride and glucose concentrations.