Iron overload is a constant and the most important complication in thalassemia. Serum ferritin concentration accurately reflects body iron stores. A total of 245 thalassemic patients aged 12–55 years were examined, 71 having Hb H disease and 174 β-thalassemia/ Hb E disease. The patients received minimal or no blood transfusions. 73 patients with β-thalassemia/Hb E were studied 1–28 years after splenectomy. The serum ferritin levels in both Hb H and β-thalassemia/Hb E patients were higher than normal. They were higher in β-thalassemia/Hb E than in Hb H disease. Most striking was the significantly higher serum ferritin levels in splenectomized patients with β-thalassemia/Hb E disease than in the non-splenectomized ones. This observation is compatible with previous observations that splenectomy in thalassemia is associated with increased iron deposition and increased transferrin iron saturation. The further increase in iron overload after splenectomy in thalassemia should be borne in mind in considering removal of this organ.