Hypochromic anemia is the commonest type of anemia encountered in family practice. Although iron deficiency is by far the most common cause, it cannot be readily distinguished from hypochromic anemia due to other causes (thalassemia, secondary anemia and sideroblastic anemia) without knowing the state of the tissue iron stores. Treatment with iron should not be commenced until this is known. To establish the reason for the hypochromic state, the following tests are suggested: serum ferritin, bone marrow assessment of iron stores, plus serum iron and iron binding capacity.