Thalassemia is a condition that affects hemoglobin synthesis and is one of the most Common hereditary illnesses in the world. Patients with thalassemia major require several blood transfusions. Multiple blood transfusions cause thyroid dysfunction, which leads to iron excess. We report the case of 35-year-old, followed in hematology for deep iron deficiency anemia who has benefited from a transfusion repeatedly diagnosed with beta thalassemia. At the interrogation, the patient reports a moderate gain of weight not quantified, hair loss and sensations of chills, chronic constipation, without other associated signs including no other signs of hypersecretion or anterior pituitary hyposecretion, no tumor SD. The physical examination finds a conscious patient, Normocardium, normal build, dysmorphic SD, palpable thyroid not increased in size. Microcytic hypochromic anemia, TSH at 10 mIU/l (0.35 -5.1) mIU / l, T4 at 10.6 pmol / l (10.6-19.4) pmol / l T3 to 2.88 pmol / l (3.8-8.4) pmol / l. Objective cervical ultrasound thyroid gland increased in size at the expense of the thyroid lobe with thyroid nodules classified EU-TIRADS 2 and 3. The patient was put on levothyrox 75ug/d. Thyroid disorders are common in β-thalassemia patients who have been transfused multiple times.