The study population consisted of 144 healthy, non-obese male adolescents, aged between 11-18 years, who were in different stages of sexual maturation as described by Tanner. The fasting plasma cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (C-HDL), low density lipoprotein cholesterol (C-LDL), and very low density lipoprotein cholesterol (C-VLDL) levels were calculated for each subject. There were significant differences observed in the following: mean TC levels between G1 and G2; mean C-HDL levels between G2 and G3 and between G3 and G4; mean TG levels between G1 and G2 and between G2 and G3; mean C-LDL levels between G1 and G2, and mean C-VLDL levels between G1 and G2 and between G2 and G3. There were no significant differences for lipids and lipoproteins between the prepubertal (G1) and postpubertal (G5) stages. It is generally believed that testosterone may play a role in mediating lipid and lipoprotein levels in the pubertal phase, but, since we found no significant differences in the levels of lipids and lipoproteins between G1 and G5, and also because these levels fluctuated from G1 to G5, it strongly suggests that the effect of testosterone on lipids and lipoproteins is dependent on other factors such as hormones, dietary habits, age, race, etc.