Congenital complete atrioventricular block without any other intracardiac anomaly reverted to sinus rhythm at the age of 7 years. The girl had had heart failure and Adams-Stokes attacks when aged 1 year, requiring pacemaker implantation. Electrocardiography confirmed sinus rhythm for the first time at the age of 7 years. At the same time, a treadmill test yielded a normal tracing without any arrhythmias.