Atrioventricular (AV) block in the neonatal period is a rare disorder. It is frequently associated with underlying structural congenital heart disease and maternal lupus. Presently described is premature baby who developed 2:1 AV block and congestive heart failure due to hypocalcemia. Dramatic clinical improvement was observed following treatment of intravenous 10% calcium gluconate. Therefore, it is suggested that serum calcium level of newborns with AV block and congestive heart failure be measured.