The aim of this study was to evaluate the alterations of the lipoprotein composition and their relation with the insulin-resistance and/or hyperinsulinemia in non diabetic obese patients. Twenty-two no obese(13 women and 9 men) and 30 obese patients (BMI > 30) were studied, who were divided into two groups according to the total lipid levels. The first group was formed by 18 obese patients (10 women and 8 men) with normal serum cholesterol (Chol) concentration < 200 mg/dL and triglycerides (TG) < 150mg/dL (NO), while the second group were formed by 12 obese patients (3 women and 9 men) with elevated Chol level > 200mg/dL and/or TG > 150 mg/dL (HO). A clinical and anthropometric examination was performed to each patient, as well as a glucose tolerance test, including serum glucose and insulin determinations. Likewise, the plasma lipoproteins (VLDL, LDL, HDL2 and HDL3) were isolated by ultracentrifugation and their cholesterol and triglycerides content were determined by enzymatic methods. In this report, we demonstrate the existence of compensatory basal hyperinsulinemia in men and women on both obese patients populations as well as alterations in the lipoprotein composition, mostly a TG overload even on NO. On the other hand, the presence of lipids and lipoproteins modification were obvious in those patients with abdominal obesity, on whom the hyperinsulinemia was more evident, which could be related with the high risk of cardiovascular disease in this kind of patients.