47 patients with thalassemia major treated with blood transfusions were studied by the authors. The aim was to carry out an investigation on caries incidence. From the data collected in this investigation it was found that 90% of males and 66% of females showed caries, then there was a difference in percentage of caries between males and females. On the other hand the dmf and the DMF index showed quite the same values in males and in females.