The objective of this study was to investigate the effects of iron supplementation and nutrition education on the iron status and anemia of middle school girls in Ulsan city in Korea. The subjects were already diagnosed as having anemia (hemoglobin < 12 g/dL) or iron deficiency (ferritin < 12 ng/mL and/or transferrin sataturation < 14 %). Over a period of three months, one iron tablet (80 mg Fe as ferrous sulfate/day) was administered to the iron deficient subjects and two tablets (160 mg Fe as ferrous sulfate/day) were administered to the anemia subjects. Total calorie intake of subjects was 82.1 % of RDA. The iron intake of subjects was 91.3 % of RDA and the Ca intake was 78.8 % of RDA. The basal hemoglobin concentration of subjects averaged 12.8 1.2 g/dL, and this increased significantly (p < 0.001) to 13.2 0.9 g/dL after iron supplementation. The basal ferritin concentrations were 14.9 14.2 ng/mL and these significantly increased to 26.6 19.8 ng/mL (p < 0.001). The level of total iron binding protein (TIBC) significantly decreased from the initial 523.1 108.7 $mu extrm{g}$/dL to 462.2 90.2 $mu extrm{g}$/dL (p < 0.001) after iron supplementation. Anemia symptoms such as‘Being bruised easily’, ‘Inflamed inner mouth’, and ‘Pale face’ improved significantly after iron supplementation in the subjects. There was a negative correlation between their class & year ranking and serum iron level, transferrin saturation after nutritional education and iron supplementation. It was shown, therefore, that the higher the improvement of their anemia level after iron supplementation, the higher their academic performance. It was shown that there was some improvement of their dietary attitudes after nutritional education, and that their serum level related to anemia symptoms and iron nutrition was improved after iron supplementation.