INTRODUCTIONVenrtricular tachycardia is the most common form of complex tachycardia and considered as a potentially fatal arrhythmia. It is associated with ischemic and nonischemic cardiomyopathies and cardiac channelopathies, and toxic metabolic conditions, or may as an idiopathic process in structurally normal hearts1. Parents with hypothyroidism or hyperthyroidism have increased risk of cardiovascular disease, such hypertension, myocardiopathy and cardiac arrhythmias. Cardiac arrhythmias associated with hyperthyroidism tend to be supraventricular, such as sinus tachycardia, atrial arrhythmias, atrial fibrillation2. It is rarely associated with ventricular arrhythmias, especially ventricular tachycardia. Here, we present a patient with hyperthyroidism who presented with ventricular tachycardia which terminated with restoration of euthyroidism. This case indicates the highly unusual presentation of ventricular arrhythmia related to thyrotoxicosis and emphasizes the management of hyperthy-roidism in patients in order to avoid potentially fatal arrhythmias.