We examined the effect of dietary behavior improvement on diet quality, body composition and blood lipid profiles in 68 middle-aged women. Dietary behavior intervention was consisted of counselling in the problem areas of portion control, food selection for low carbohydrate and high fiber food items, and education on the improvement of micronutrient intakes and diet quality. The subjects were divided into two groups; Improved or Not-Improved Group according to the level of changes in dietary behavior scores. After 6 months, body weight, BMI, waist-hip ratio, and visceral fat area were significantly decreased in the Improved Group compared to the Not-Improved Group. Calorie-adjusted protein, fiber, calcium, iron and vitamin C intakes were significantly increased in the Improved Group. The index of nutritional quality (INQ) and mean adequacy ratio (MAR) were increased only in the Improved Group. We observed a significantly increase in HDL-cholesterol and a decrease in total cholesterol, triglyceride and LDL-cholesterol, and an improvement of atherogenic index in the Improved Group. These results showed that dietary behavior intervention improved dietary behavior scores, and those whose dietary behavior score improved showed more improvement in diet quality, body composition, and serum profiles than those whose dietary behavior score did not improve.