Purpose: The Mediterranean diet has been reported to reduce cardiovascular mortality and morbidity considerably. Tomatoes and lycopene are considered potent antioxidants. Our purpose was to study the effects of a tomatoe-rich diet on the lipid profile following 300g daily of tomatoes for one month. Methods: Plasma concentrations of triglyceride, total cholesterol, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol were determined in 98 apparently healthy volunteers (mean age 45.5 +/- 14.1yr) before and after one month of follow-up. Fifty volunteers (34 women and 16 men) ate tomatoes 300g daily and 48 volunteers (32 women and 16 men) continued their regular diet without eating tomatoes for a month. Results: In the regular diet group, there were no changes in the lipid profile: triglyceride level (169.6 +/- 156.8 vs. 147.6 +/- 93.4m/dl; P=0.33), g I total cholesterol level (198.3 +/- 41.2mg/dl vs. 204.2 +/- 70.9mg/dl; P=0.23), HDL-cholesterol level (50.6 +/- 12.2mg/dl vs. 47.6 +/- 10.8mg/dl; P=0.79), and LDL-cholesterol level (122.7 +/- 39.4mg/dl vs. 120.2 +/- 32.2mg/dl; P=0.24) before and after the I month of follow-up. In the tomato-rich diet group: triglyceride level 170.8 +/- 85.4mg/dl to 167.4 +/- 99.4mg/dl; (P=0.98), total cholesterol level 207.5 +/- 44.3mg/dl to 204.1 +/- 45.1mg/dl (P=0.68), HDL-cholesterol level 46.1 +/- 10.6mg/dl to 53.4 +/- 13.3mg/dl (P=0.03), and LDL-cholesterol level 127.7 +/- 41.8mg/dl to 119.1 +/- 41.7mg/dl (P=0.57). Conclusion: We found that tomatoes'-rich diet (300g daily for one month) increased HDL-cholesterol level significantly by 15.2%.