Introduction: The risk of cardiovascular morbidity and mortality is high in non insulin-dependent diabetics and control of hyperlipidemia is a major concern in these patients. Hypercholesterolemia and hypertriglyceridemia very frequently are the result of poor glycemic control. Improved glycemic control, even if not perfectly normal sugar values are achieved, in non insulin-dependent diabetes mellitus (NIDDM) with sulfonylurea therapy is usually accompanied by decreases in plasma lipids.Objective: The purpose of this study was to compare the effectiveness of exogenous insulin to that of sulfonylurea agents on the control of lipid levels in patients with NIDDM.Material and Methods: 70 patients with NIDDH and dyslipidemia were studied. They were divided in two groups.Group I consisted of 52 patients (29 females and 23 males) with mean age 63.5 yrs who were treated with oral antidiabetic drugs (sulfonylureas). Group II consisted of 18 patients (12 females and 6 males) with mean age 63 yrs who were treated with intermediate acting insulin. Body weight in Group I was 73.4 ± 9.9 kgr (m ± SD) whereas in Group II was 71.5 ± 8.08 kgr (m ± SD). Serum concentrations of glucose, total cholesterol, triglycerides and HDL-ch levels were determined in both groups before, 6 and 12 months after treatment.All subjects were in nonpharmacological therapy (diet, exercise) for at least 6 months prior to the study.Data were analyzed by regression analysis. Control of hyperglycemia achieved was similar in both groups (p < 0.05).The results are summarized in the table (mean ± SD).Results: In Group I (Sulfonylurea Rx) there was a positive correlation between the levels of glucose and the levels of total cholesterol (F = ±8.01; p < 0.05 before, 6 and 12 months after treatment. In Group II (Insulin Rx) there was a significant correlation between glucose and triglycerides levels (regression analysis (T = 3.33; p < 0.05) before, 6 and 12 months after treatment. There was no significant correlation in both groups between body weight and change of lipids and glucose.Conclusion: Our results support the notion that the improvement on lipid profile in non insulin-dependent diabetics is associated with good glycemic control regardless of the way by which this is achieved be that sulfonylureas or exogenous insulin ie. it is not a direct effect of sulfonylureas or exogenous insulin. Patients receiving hypoglycemic drugs or insulin therapy should also continue to try to achieve weight loss through diet and physical activity.