We carried out total body computerized tomography (CT) studies and examined the retrospective clinical data of 29 adult patients with thalassemia intermedia (TI) to evaluate the incidence, features and pathogenesis of ectopic erythropoiesis (EE), located chiefly at the paravertebral gutters in the thorax, was present in 65.5% of the patients; 15% of them had severe clinical complications. We found a clear relationship between EE development and early presentation age of thalassemia, splenectomy and the presence of 100% fetal hemoglobin. The frequent occurrence of EE suggests that CT screening of patients with thalassemia intermedia should be mandatory. We also recommend radiotherapy as a preventive measure for the clinical complications of thalassemic patients with EE.