This study was performed to determine plasma carnitine concentrations and to investigate whether plasma carnitine concentrations and serum biochemical parameters are affected by dietary carnitine supplementation in lambs. Thirty male Merino x Kivircik crossbred (F1) lambs were divided into three groups as control, treatment 1 and 2. All animals were fed with alfalfa hay and compound feed for 45 days. In additon, the treatment groups 1 and 2 received L-carnitine (100 and 200 mg/day, respectively) mixed into compound feed. On the 25(th) and 45(th) days of the experiment, carnitine and glucose concentrations were higher in the treatment groups as compared to the control, while the concentrations of cholesterol and triglyceride were lower in the treatment group 2 than the other groups. Serum total protein concentrations were not affected by the additional amounts of dietary carnitine. A decrease at the concentrations of cholesterol and triglyceride in the carnitine administered groups was observed, implying that the carnitine supplementation might improve lipid utilization in lambs. Additionally, an increase at plasma carnitine concentrations after carnitine supplementation was obtained, which might indicate that at least a portion of the dietary carnitine might be absorbed without any degradation process in rumen.