Dofetilide is a class III anti-arrhythmic drug that has been approved for the treatment of atrial fibrillation. Two clinical studies, which enrolled 996 patients, demonstrated pharmacological conversion to sinus rhythm to occur in 30% of patients. Following pharmacological or electrical conversion, median time to relapse exceeded one year. Two large clinical studies that enrolled 3028 patients have been performed in high-risk patients with severe heart failure and large myocardial infarctions. The outcomes of these studies were neutral with respect to survival and demonstrated the safety of dofetilide. After pharmacological or electrical conversion of atrial fibrillation to sinus rhythm in these studies, the probability of remaining in sinus rhythm during the following year was 75%. Dofetilide has a single significant side effect: risk of developing torsade de pointes ventricular tachycardia. Therefore, dosage must be carefully adjusted to the length of QTc interval, calculated creatinine clearance and the presence of heart failure or recent infarction. In addition, treatment must be initiated in hospital with three days of continuous telemetry. Dofetilide can be co-administered with digoxin and beta-blockers. Other anti-arrhythmic drugs, as well as drugs that interfere with the renal elimination or the metabolism of dofetilide, must be avoided. Dofetilide is an option when persistent atrial fibrillation is a clinical problem. In the setting of severe heart failure and large myocardial infarctions, only amiodarone and dofetilide have proven safety and dofetilide is a strong candidate for first choice treatment when the aim is to achieve sinus rhythm.