We read with interest the article by Nalbantoglu et al. . In their article, it was stated that the valid formulas calculated from erythrocyte indices on automated blood counts are not sufficient to discriminate between thalassemia minor (TM) and iron deficiency (ID) in pediatric patients. It is also reported that the most reliable discrimination between these two entities might be done using the parameters of body iron status (serum iron down arrow, serum iron binding capacity up arrow, and serum ferritin.) and hemoglobin A2 (HbA2 up arrow) level. These tests, if available, were suggested for achieving a definite diagnosis in every case with microcytosis. Based on our experience [2-6], we do agree with the authors' opinion regarding the incapability of the formulas to discriminate between these two entities. However, we would like to emphasize that the parameters suggested by the authors might also prove insufficient in some particular situations. With this letter, we want to point out those particular clinical conditions. These conditions should be taken into consideration in discriminating between TM and ID.