A 2-year-old male patient, asymptomatic with bradycardia (40bpm) in a routine examination. Using electrocardiogram the diagnosis of complete atrioventricular block (CAVB) was made. Echocardiogram was performed and showed no functional or structural disease. We conclude like an asymptomatic congenital isolated CAVB with insufficient ventricular rate, for this reason a permanent pacemaker (VVI mode) was implanted, without complications.