Introduction: Patients with thalassemia major often present with a hypercoagulable state, the pathogenesis of which is still not understood. Materials and Methods: This study evaluates the risk factors for hypercoagulability in 50 β-thalassemia major patients and 50 healthy controls. Fasting total homocysteine, protein C (PC), protein S (PS), antithrombin (AT), activated protein C resistance (APCR) and lupus anticoagulant (LA) were assessed. MTHFR C677T mutation was determined. Results: Significant reductions in PC, PS and AT were noted in patients. Only 4% of the patients had hyperhomocysteinemia. Thirty-two percent of the patients were heterozygous and 4% were homozygous for MTHFR C677T mutation. Conclusion: The natural coagulation inhibitors PC, PS and AT were significantly reduced in patients with β-thalassemia major and were thus important risk factors for the hypercoagulable state, but hyperhomocysteinemia and MTHFR mutation do not seem to be significant risk factors for thromboembolic events.