Combination chelation therapy with desferrioxamine and deferiprone has recently been suggested as a more effective tissue iron-chelating treatment for transfusion-dependent beta-thalassemia patients, although a standard dosage protocol has not yet been established. We describe a thalassemia major patient who had been treated with combination therapy with desferrioxamine and deferiprone and who was referred to us for faintness and dizziness associated with electrocardiographic ST-T changes and arrhythmia. A brief interruption of the treatment and a subsequent decrease in the drug doses caused the reversion of symptoms and findings. This response prompted us to speculate that a causal relationship existed between the observed abnormalities and the intensive chelation therapy. The possibility of this electrical instability as an adverse cardiac event occurring in the context of treatment with these chelating agents raises questions about the time of application of this therapy, the regimen dosages, and follow-up of such patients.