İn the study, changes in iron and ferritin concentrations in the blood serum of β-thalassemia patients receiving desferal therapy were studied. 125 One patient with β-thalassemia was examined. 68 of them were boys and 53 were girls. The control group consisted of 20 healthy people. Depending on the clinical course of the disease, the examined patients were treated with desferal in different doses. After taking Desferal, the concentration of ferritin in the blood of patients was determined. Thus, the decrease in the concentration of ferritin depends on the dose of Desferal. Thus, the use of desferal therapy in the treatment of β-thalassemia patients has been shown to be appropriate. The determination of ferritin in the blood serum can play an important role in maintaining the normal level of liver and spleen function in this group of diseases, allowing for accurate selection of desferal dose dynamically.