Congenital Heart Block (CHB) is the most serious complication of neonatal lupus erythematosus. Transplasental transfer of maternal anti SSA/Ro or antiSSB/La antibodies around 12th week of gestation is associated with development of CHB. This may lead to inflammation, fibrosis and scarring of fetal conduction system in the early second trimester. Different degrees of atrioventricular (AV) block may be seen in the affected fetus. First and second-degree AV blocks may change in severity; however, third degree AV block is irreversible. CHB is mostly diagnosed between 18 - 24th weeks of gestation. Even if most of the mothers carrying autoantibodies of several rheumatic diseases such as systemic lupus erythematosus or Sjogrens syndrome are not aware of their diseases until their children are born with CHB, it is recommended that antibody-positive mothers or the mothers having babies with neonatal lupus erythematosus should be referred for close fetal echocardiographic surveillance beginning from the early second trimester. Although their utility is still controversial, various therapeutic regimes such as sympathomimetic, plasmapheresis, steroids, intravenous immunoglobulin, digoxin, diuretic and in utero pacing have been used for intrauterine treatment of CHB. Aggressive medical treatment is coupled with pacing in infants who do not respond to medical therapy alone.