A case of long QT syndrome diagnosed in the early neonatal period is described. This full-term female baby had intermittent atrioventricular (AV) block and ventricular tachycardia detected antenatally at the gestational age of 26 weeks. Sinus rhythm with prolonged QT interval (QTc = 0.636 sec) was found soon after birth. She developed variable degree of AV block with alternating left and right bundle branch block, which suggested the presence of multilevel AV block. Her mother had no lupus autoantibodies. Auditory brain stem evoked potential was normal. Family study revealed QT prolongation in her grandmother. Her condition improved after pacemaker implantation and oral beta-blocker usage.