The endocrinological complications in a-thalassemia major patients do affect the life quality to a large extend. In this study, the endocrinological complications of 47 beta-thalassemia patients, who have been followed-up at our hospital's pediatric hematology department, were evaluated. Out of beta-thalassemia major cases included to this study, the 55.3% was male and 44.7% was female. The patients' mean levels of ferritin, whosemean age was 10.0 +/- 4.5 years (2-20 years), were 2497 +/- 1469 ng/mL (472-8558 ng/mL). At least one endocrinological pathology in 27 out of 47 (57.4%) and more than one endocrinological pathology in 14 out of 47 (29.7%) thalassemia patients were observed. The most frequently observed complication in followed-up cases was vitamin D insufficiency and deficiency (78.2%). The other complications in decreasing order were pubertal failure (41.6%), growth retardation (25.5%), decreased bone-mineral density (22.2%), secondary hyperparathyroidism (11.5%), overt hypothyroidism (4.25%), subclinical hypothyroidism (2.12%), and impaired glucose tolerance (2.12%). There was no statistically significant difference between serummean ferritin level and endocrin complications (P > .05). Four patients (8.5%) had decreased signal intensity in pituitary magnetic resonance imaging (MRI) but this finding was not associated with ferritin levels (P = .87). MRI parameters were similar between patients with and without gonadal dysfunction. Mean height of the pituitary gland was 4.98 +/- 1.1 mm (3-9 mm) and this was similar to those normal values in the literature. Ferritin levels were not correlated with pituitary height (P > .05). Beta thalassemia major, having the potential of leading to multisystemic complications, is a chronic disease that should be treated and followed-up by a multidisciplinary approach. Due to frequently encountered endocrinological complications, beta thalassemic patients should be followed-up regularly by hematology and endocrinology departments in coordination.