The occurrence and the duration of paroxysmal atrial fibrillation (AF) are influenced by vagal tone. Paroxetine, an antidepressant, can modulate vagal tone at the level of the mid-brain and inhibit the vasovagal reflex. In this study, oral paroxetine 10 mg/day was administered to patients with multidrug-resistant paroxysmal AF. Nine consecutive men responded favorably to the drug. In 3 patients, AF resolved completely. One patient could not tolerate the drug because of nausea and nervousness. These preliminary results suggest that paroxetine could be a choice in the pharmacologic treatment of paroxysmal AF.