Fetal atrioventricular block (AVB) is a type of fetal bradyarrhythmias. The reported incidence of fetal complete atrioventricular block (CAVB) and mortality of perinatal fetuses and neonates are significantly higher in pregnancies of anti-SSA/Ro-positive mothers than that of anti-SSA/Ro-negative mothers. The auto-antibodies in maternal serum that can be transported into fetal circulation through placenta may damage fetal cardiac conductive system and eventually result in fetal AVB. There are evidences that early diagnosis and proper treatment can improve the prognosis and survival rate of affected fetuses. In this article, the pathogenesis, risk factors, prenatal diagnosis, treatment and prognosis of fetal immune mediated AVB is reviewed.