The purpose of this study was to compare food behaviors, nutrient intake, clinical symptoms, and hematological findings by smoking status. Among the third grade male students from a high school in Jinchun-kun, 31 smokers and 31 nonsmokers participated in this study. A self-administered questionnaire was used to investigate food behaviors and clinical symptoms. Nutrient intake data were collected by 24-hour recall method. Blood sample was drawn from each subject to determine the levels of hemoglobin, protein, triglyceride, cholesterol, etc. The major findings were as follows; First, smokers consumed every food group except fat & oil less frequently than nonsmokers, while they consumed instant food, coffee, alcoholic beverages more frequently than nonsmokers. Dietary habits of smokers such as regularity, balanced diet, skipping meals were worse than those of non-smokers. Second, intakes of energy, fat, carbohydrate, and β-carotene of smokers were lower than those of non-smokers. Third, smokers felt fatigue and other adverse symptoms more often than non-smokers. Fourth, the levels of hemoglobin, albumin and HDL-cholesterol were significantly lower in smokers than non-smokers. Fifth, Smoking history was negatively correlated with food behaviors, energy intake and clinical symptoms. These results suggest that food behaviors, nutrient intakes, hematological findings and clinical symptoms of male high school students were affected by smoking. Therefore, in order to decrease smoking rate of the students, the effect of smoking on nutritional and health status should be informed and nutrition education should be offered to the students.