We report the results of a single-center, prospective evaluation for iron overload and subsequent treatment in 147 adult allogeneic hematopoietic cell transplantation (HCT) recipients who survived beyond 1 year after transplantation. Patients were screened by serum ferritin level; those with ferritin >1000 ng/mL underwent liver R2 magnetic resonance imaging to estimate liver iron concentration (LIC; normal < or =1.8 mg/g). Patients with significant iron overload (defined as LIC > or =5 mg/g), based on physician and patient preference, were offered observation only, phlebotomy, or enrollment in a pilot study of deferasirox. Sixteen patients had significant iron overload. Their median age was 51 years (range, 29-64 years), and they had survived a median of 21 months (range, 12-114 months). All 16 patients were transfusion-independent at study enrollment. Five patients received no treatment (median LIC, 6.4 mg/g; range, 5.1-28.3 mg/g), 8 underwent phlebotomy (median LIC, 13.1 mg/g; range, 7.8-43.0 mg/g), and 3 received daily deferasirox 20 mg/kg/day orally for 6 months (LIC, 6.3, 9.0, and 19.9 mg/g). Two patients had abnormal liver function tests, and 1 patient each had cirrhosis and unexplained congestive heart failure; all 4 of these patients underwent phlebotomy. Follow-up serum ferritin concentrations decreased spontaneously in 4 patients in the observation-only arm. Phlebotomy was generally well tolerated. Deferasirox also was well tolerated and led to decreased LIC after 6 months of therapy in all 3 patients. Phlebotomy is feasible in the majority of allogeneic HCT recipients who have survived for > or =1 year after HCT and have significant iron overload. Although the number of subjects is small, deferasirox may be a safe and effective alternative for allogeneic HCT survivors with iron overload who cannot undergo phlebotomy.