Bone marrow transplantation (BMT) is the only complete cure for b-thalassemia. Iron depletion therapy is still required to remove excess iron, accumulated before BMT. Hepatic and myocardial iron load were evaluated using T2* magnetic resonance in 8 ex-thalassemic patients after BMT, aged 19.5 +/- 4.25 years, who were in iron depletion therapy. Average hepatic T2* was 18.8 +/- 11.0 msec (4.1-35.0 msec). In 4 out of 8 patients iron overload was detected, not exceeding however 4 mg/gr dry tissue. Average heart T2* was 31.0 +/- 4.6 msec (25.6-35.2 msec), not significantly different (P = 0.18) from our age-matched normal population (33.0 +/- 4.0). Normal left ventricular ejection fraction was found in 7 out of 8 patients (mean 64.5 +/- 7.0%) with the remaining having a marginal value of 54.1%. Ferritin level before BMT was 1748 +/- 451 mug/l and dropped to 536 +/- 260 microg/l at the end of iron depletion therapy after BMT. Current ferritin level was 271 +/- 253 microg/l and although it was significant lower compared to both ferritin before BMT (P < 0.001) and after iron depletion (P < 0.001), evidence of residual hepatic iron load was identified by T2*. Hepatic and myocardial T2* magnetic resonance can be used as a more reliable index than ferritin for evaluation of iron depletion therapy in ex-thalassemic patients after BMT.