This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Abstract Diagnostic and treatment challenges of congenital complete atrioventricular block in two premature newborn babies are presented. Timely recognition of this fetal condition, appropriate antenatal care, and treatment at a tertiary level care hospital as well as prompt postnatal management of the newborn baby are the key factors for good outcome. Prematurity is also associated with an additional risk of poor outcome and complications. K E Y W O R D S dilated cardiomyopathy, fetal bradycardia, isolated congenital complete atrioventricular block, pacemaker implantation, premature newborns 1198 | GEGIECKIENĖ Et al.