In a retrospective analysis we assessed the data of 46 patients with myelodysplastic syndromes (MDS), who had received more than 50 blood transfusions during the course of disease. The number of units given ranged from 50 to 155 (mean 79). 20 patients (RA n = 4, RARS n = 12, RAEB n = 1, RAEB/T n = 2, CMML n = 1), followed up between 8 and 108 months (mean survival time 39.4 months), developed a secondary hemochromatosis. More than 40% of the patients showed signs of heart failure, in some cases accompanied by cardiac arrhythmias. 11 patients also suffered from hepatopathy and 5 developed diabetes mellitus. Secondary hemochromatosis was particularly common in patients with RARS. Refractory congestive heart failure secondary to hemochromatosis was the cause of death in 14 patients, whereas none died from hepatic insufficiency. We conclude that the risk of secondary hemochromatosis should not be neglected in polytransfused patients with MDS. In some cases, particularly those with favorable prognostic features of MDS, it may shorten life expectancy. The availability of a new oral iron chelator (1,2-dimethyl-3-hydroxypyrid-4-one or L1) offers a promising and practicable approach to prevent this complication.