Alterations in plasmatic lipid profile are known to be risk factors for atherosclerotic disease and have been associated with obesity. This research was designed in order to study the incidence of these alterations in obese children and adolescents according to two different reference patterns. Analyses of seric levels of Total Cholesterol (CT) and fractions and of Triglycerides (TG) were done. The sample included 74 obese children and adolescents with average age equal to 11 years and 10 months for boys and 10 years and 9 months for girls and with mean weight/height ratio (W/H) equal to 151 and 149% for boys and for girls, respectively. Plasmatic lipid values obtained were classified according to the American Heart Position Statement Circulation (AHPSC) and to Kwiterovich reference patterns. It was observed that patients with abnormal seric HDL-cholesterol (HDL) levels had a significantly greater (W/H) then the other group. It was also noticed that a greater number of individuals presented abnormal or borderline plasmatic lipid levels (91.9%), specially HDL (93.6%) and TG (67.6%), according to Kwiterovich than AHPSC. Obesity showed to be an important factor in determining lipid profile values and should be included as a variable to indicate screening of these lipoproteins in childhood and adolescence.