Background and objectives: β-thalassemia major patient is one of the hereditary hemolytic diseases, which can cause many hematological and biochemical changes in the affected patient. And these changes can happen even when the patient is treated adequately. The objective was to study biochemical changes in the level of serum hepcidin, osteocalcin, calcium, ferritin, iron, PTH and IL-6 in patients with β-thalassemia major and to compare it with control subjects. Patients and method: In this research 40 patients with beta thalassemia major, 20 Female and 20 Male (age ranged from 10 to 38 years), and 40 control subjects 20 Female and 20 Male (age ranged from 9 to 33 years) were studied. Measurement of serum hepcidin, osteocalcin, calcium, ferritin, iron, PTH and IL-6 were done by the researcher for both cases and control groups. Results: Serum Ferritin and Iron were higher significantly in all thalassemic patients (P< 0.001), this increment was proportional with increasing number of units of blood transfusion and aging. Mean serum Hepcidin, PTH, Osteocalcin and IL6 were significantly lower in thalassemic patients in contrast to the control subjects (P< 0.001). Reduction in S-PTH was proportional to increasing number of blood transfusion and aging. But there was no significant difference in the level of serum Calcium in the majority of patients, only 9 patients had low serum calcium. Conclusion: Our study demonstrates that in B-thalassemia major patients Serum Ferritin and Iron were increased proportionally with increasing age and number of units of blood transfusion. Mean serum PTH, osteocalcin, hepcidin, and IL-6 were reduced, but mean serum calcium was remained normal.