en Infectious Diseases Infectious Diseases Original Article Original Article Background: One of the most common endocrine problems in major beta-thalassemia is hypothyroidism (HT). The aim of this study was to evaluate thyroid function status in major beta-thalassemia patients older than 10 years old. <br>Methods: This cross sectional study was carried out on thalassemia major patients registered on Thalassemia Center of Amirkola Children Hospital in Babol. A questionnaire was filled out by the patients to evaluate the demographic information, quality of their last transfusions and chelation therapy. Growth parameters were evaluated. We assessed serum T₄, TSH, T₃RU and FTI in all patients and those with hypothyroidism, anti-thyroglobulin and anti-thyroid proxidase antibodies were checked. Results: One hundred-thirty patients (56 males and 74 females) were enrolled in this study. The mean age was 20.95±7.8 years. Short stature was seen in 41(31.3%) patients. In 53(40.8%) patients, weight was under normal range. HT was found in 19 patients (14.6%) 2 primary overt HT, 3 secondary HT and 14 subclinical HT were detected. No patient with HT had significant serum level of anti-thyroid antibodies. Correlation between HT and serum ferritin level was not significant (p=0.584) but it was significant for HT and short statures (p=0.002), also regular transfusion and chelation therapy were correlated with ferritin level. <br>Conclusion: High prevalence of HT among thalassemic patients signifies the importance of regular screening for evaluation of endocrine function in these patients especially when short stature is present. Major thalassemia, Hypothyroidism, Serum ferritin 189 193 http://caspjim.com/browse.php?a_code=A-10-62-40&slc_lang=en&sid=1 Peiman Eshragi 1003194753284600377 1003194753284600377 Yes Ahmad Tamaddoni 1003194753284600378 1003194753284600378 No Khadijeh Zarifi 1003194753284600379 1003194753284600379 No Amir Mohammadhasani 1003194753284600380 1003194753284600380 No Majid Aminzadeh 1003194753284600381 1003194753284600381 No