Introduction: Incidence of congenital complete atrioventricular block (CAVB) is 1 per 20 000 live births. Mostly it is caused by maternal anti-Ro/La antibodies but can be associated with congenital heart diseases or sporadic in caused by gene mutations. Aim: Aim is to identify the most common etiology for congenital CAVB and treatment principles. Materials and methods: In this retrospective study medical histories of 13 patients with CAVB were collected and analysed. Collected data included age at diagnosis, gender, presence of maternal anti-Ro/La antibodies, ventricular rhythm at birth, type and time of treatment, and outcome. Diagnosis was compared in two groups of patients- neonatal lupus patients and non-immune patients. Results: Of all 13 patients maternal anti-Ro/La antibodies were found in 10 cases and in 3 cases, maternal anti-Ro/La antibodies were absent. Eleven patients were diagnosed prenatally with a mean age at diagnosis 24,82 ± 6,9 gestational weeks and postnatal were diagnosed 2 patients with a mean age at diagnosis 97 ± 134,3 months. Prenatally diagnosed patient mean ventricular rate at birth was 62 ± 11.6 beats per minute. Of all patients with congenital CAVB 10 underwent pacemaker implantation but 3 had no indications for pacing so far. Of the prenatally diagnosed patients who underwent pacemaker implantation 6 had urgent pacemaker implantation whith mean age at implantation 8,3 ± 4 days but 3 had delayed pacemaker implantation with mean age at implantation 21.02 ± 17.76 months. One (7,7%) patient from the total died. Conclusions: Maternal lupus antibodies are the most common cause of congenital CAVB. Non- immune congenital CAVB was mostly diagnosed postnatally, when compared to neonatal lupus patients. Due to the small number of patients there is insignificant data showing the difference between groups and time of pacemaker implantation. Ventricular rate <60 bpm is main predictive factor for urgent pacemaker implantation. [ABSTRACT FROM AUTHOR]