This work investigated the viability of the portable x-ray fluorescence (PXRF) technique as a means of measuring iron levels in patients suffering from thalassemia major (beta-thalassemia) and hereditary hemochromatosis (HH or Haemochromatosis) or other iron-overload conditions. Measurements were conducted at the University Hospital Blood Center and in the Laboratory of Applied Nuclear Physics at the State University of Londrina, Brazil. One thalassemia major patient and four healthy people were grouped. A PXRF system consisting of a Pu x-ray source and a SiPIN diode detector was used for measurements in vivo on the hand of each patient. The measuring system was calibrated with phantoms of aqueous solution doped with 15 to 150 ppm of iron. The duration of each measurement was 50 s. The detection limit (LLD) reached for iron was 13 ppm. The radiation dose on the skin was 10 mSv. The thalassemia patient presented 74 ± 6 ppm of iron, whereas the healthy people presented an average of 53 ± 5 ppm of iron. The results are in accord with the literature, which shows iron levels in the skin to be between 15 - 60 ppm for healthy people and between 70 - 150 ppm for thalassemia major patients. This work concluded that it is viable to apply the XRF methodology to follow thalassemia major and HH patients.