Abstract Background & Objectives: Thalassemia syndromes isone of the inherited disorders in which one or more globulin chains are affected. On the basis of clinical symptoms, thalassemias are categorized as minor, intermediate, and major. Minor beta -thalassemia is a mild microcytic hypo chromic anemia in most cases asymptomatic and HbA2 is more than normal. Materials & Methods: This study carried out on 813 blood samples obtained from male high school students of Aliabad Katool, in the north of Iran. After detecting red blood cell indices of the subjects whose MCV was less than 80fl HbA study performed. Results: The MCV of 8.24% of the subjects was less than 80fl.34 of 67 had HbA2 of less than 3.5 %(normal) while the rest more than 3.5%(minor). Conclusions: Since about 50% of microcytic anemic patients were the carrier of beta-thalassemia and it is highly Prevalent in this region (4.06%), we recommend to investigate HbA2 in people with MCV less than 80 fl. Keyword: Thalassemia, Thalassemia minor, HbA2, Iran