Background: Considering the great importance of iron deficiency, anemia, and iron deficiency anemia as one of the most important indices of public health, the present study was carried out over the high school students in Varamin in 1998-99 to determine the prevalence of iron deficiency, anemia and iron deficiency anemia. Materials and methods: 799 students, including 466 females and 333 males had been randomly selected for this descriptive study. Then, demographic data were collected and HGB, HCT, MCV, MCH, MCHC, ferritin, iron and TIBC were all measured by means of a standard technique. The prevalence of iron deficiency, anemia and iron deficiency anemia were determined according to the latest WHO criteria. Results: The prevalence of iron deficiency, anemia, and iron deficiency anemia were 13.9%, 34.5%, and 7.6%, respectively. (16.3%, 43.7%, and 10.5% in females vs. 10.5%, 21.6%, and 3.6% in males). Disorders were more prevalent in females. Anemia has revealed to have moderate prevalence, where iron deficiency had high prevalence. Iron deficiency was the leading cause of anemia (>50%). Conclusion: More studies are strongly recommended to determine the etiology of iron deficiency; meanwhile, interventional researches seem to be beneficial.