We report a clinical case of a patient with NSCLC who experienced an atrial fibrillation during paclitaxel infusion. Before chemotherapy, his cardiological function was normal. No cardiovascular and/or thyroid associated disease were previously reported. The patient did not receive any drugs with pro-arrhythmic effects. Incidence of cardiovascular toxicity in patients treated with paclitaxel is low, and does not justify strict cardiological monitoring otherwise deserved to patients with preexistent risk factors.