Although arrhythmias are common in hypertrophic cardiomyopathy (HCM), complete atrioventricular (AV) block is very unusual. A 27-year-old female presented with a recent history of syncope and exercise intolerance. ECG demonstrated complete AV block. Two-dimensional Doppler echocardiography revealed HCM with a 60 mmHg left ventricular outflow tract (LVOT) gradient. A temporary transvenous ventricular pacemaker was inserted urgently, and subsequently replaced by a permanent DDD pacemaker. All symptoms were eliminated. This symptomatic improvement was associated with complete disappearance of LVOT gradient at the time of implantation. No gradient was observed during early follow-up and at 6 months after DDD pacemaker implantation.