We measured the iron content of the spleen in 12 patients with thalassemia major, three with thalassemia intermedia, and one with sickle-thalassemia. The iron content was unexpectedly low in all patients (0.25-2.4 g, median 1.32). These data suggest that iron deposited in the reticuloendothelial cells of the spleen is rapidly removed and redistributed throughout the body. The preferential removal of iron from the spleen did not seem to be a result of chelation therapy.