BACKGROUND: Atrial Fibrillation (AF) presents gross economic problem for health care payers. Atrial based pacing is an accepted method of treatment of bradycardia-tachycardia syndrome (BRTS). OBJECTIVES: to compare resource utilization and costs of care in BRTS before and after atrial based pacemaker implantation. METHODS: Observational, retrospective, unicenter study included 145 pts (84F; 61M; mean age 68,5) with BRTS, paroxysmal AF and atrial based pacing system (AAI 64,8%; DDD 35,2%) implanted during one year. The data on utilized resources were collected in time window: from 1 year before implantation to 3 years after implantation. The costs were calculated from the public health care payer perspective. RESULTS: During the 3 years after implantation 20 patients died (13,8%) and the cost analysis was performed among survivors. At least one AF episode was reported in 103 pts (82,4%) and 19 (15,2%) had chronic AF at the end of study period. There were 338 AF related hospitalizations before implantation (mean 2,7 per year, per patient) compared to 423 (during 3 years; mean 1,13 per year, per patient; Wilcoxon test p<0,001). The distribution of costs before implantation was: hospitalizations 82,0%, drugs 10,7%, consultations 4,1%, AF complications (mainly stroke) 3,2% and after implantation: hospitalizations 38,3%, followed by drugs 24,4%, pacing complications costs 21,1%, consultations 6,1%, pacemaker follow-up 4,2% and AF complications 5,9%. The mean annual cost of care of AF decreased after implantation from 3138 PLN (~1569 Euro PPP) to 1923 PLN (~961 Euro PPP) (p<0,001) and the savings were mainly associated with lower hospitalization rate which was not only economic but also clinical profit. CONCLUSIONS: Atrial based pacing decreases number of hospitalizations and overall costs of therapy in bradycardia-tachycardia syndrome. Hospitalizations due to AF represent the major cost driver in group of patients with brady-tachy syndrome.