Introduction: Diet is the cornerstone of management for all patients with hyperlipidemia and should be used before any pharmacologic intervention. Patients with hypercholesterolemia and normal weight should be placed on isocaloric diet with reduction in total and saturated fat and cholesterol to the extent which can be tolerated by the patient. While there is a significant reduction in triglycerides after diet and weight loss, only 5-15% reduction in the total cholesterol can be expected after hypocholesterolemic diet. There is also a significant individual variability in the efficacy of diet. Approximately 30% of patients are diet insensitive and their cholesterol levels change little when placed on a step III diet.Patient-Materials: The aim of our study was to estimate the role of dietary therapy in the management of hypercholesterolemic patients of Northern Greece, a population with generally low total and saturated fat consumption. 75 hypercholesterolemic subjects (33 males and 42 females), aged 41-75 (mean age 56.9) were examined in our lipid clinic. All patients were evaluated and received instructions for dietary modifications. Blood samples for lipid profile were taken before, 3 and 6 months after.Results: Our results showed that the average reduction of total cholesterol was 4.14% (from 264 mg/dl to 252 mg/dl) and 6.88% (from 264 mg/dl to 244 mg/dl) after 3 and 6 months respectively, while the average reduction of LDL was 6.8% after 3 months and 9.9% after 6 months. Of the 75 hypercholesterolemic subjects, only 17 (22.6%) reduced their total cholesterol more than 15%, while 27 subjects (36%) had reduction of less that 5%. The average reduction of total cholesterol in women was 5.8% and in men was 7.96%. 40 (53%) of our patients achieved weight loss averaging 3.2 Kg. 29 patients (38.6% of the total) found it difficult to follow this diet.Conclusions: The small reduction of total and LDL cholesterol may be attributed also to the fact that the majority of our patients were already on some form of Mediterranean diet and there was no significant switching in their dietary habits.