IMPORTANCE OF THE FIELD: Dronedarone is developed for treatment of atrial fibrillation (AF) or flutter (AFL). It is a noniodinized amiodarone analogue and believed to be without the adverse effects of amiodarone. However, long-term adverse effects are not yet well investigated. AREAS COVERED IN THIS REVIEW: This is a review of seven studies on dronedarone. WHAT THE READER WILL GAIN: DAFNE established an effective dose to be 400 mg b.i.d. ADONIS and EURIDIS showed significant prevention of AF/AFL recurrence hazard ratio (HR 0.78 and 0.73) compared to placebo. In ATHENA, cardiovascular death/hospitalization was significantly reduced (HR 0.76) in patients with AF and additional risk factors. ANDROMEDA was stopped because dronedarone increased early mortality (HR 2.13) in advanced heart failure (HF). ERATO found that dronedarone significantly reduced heart rate compared to placebo in patients with AF. DIONYSOS showed that amiodarone was superior to dronedarone to maintain sinus rhythm in patients with AF/AFL. TAKE HOME MESSAGE: Dronedarone is superior to placebo but less efficient than amiodarone in maintaining sinus rhythm in patients with a history of AF. In patients with AF and risk factors dronedarone reduces cardiovascular mortality and morbidity, but in patients with severe HF dronedarone significantly increases mortality.