This study focuses on the question of the epidemiology of resistance to antibiotics in Acinetobacter baumannii, which is nowadays one of the most problematic bacterial patho- gens associated with failing antimicrobial therapy. Its aim was to define population-genetic properties, epidemiology and the nature of multidrug resistance for a sample of the current population of A. baumannii from Czechia. A total of 55 isolates were collected in eight medi- cal facilities in central Bohemia from October 2016 to May 2018. The isolates were assessed for their identity at the species, clonal and strain levels as well as resistance phenotype and genotype; they were classified into five clonal groups, each of which encompassed isolates that were likely to be epidemiologically related. The 55 isolates studied belonged, nearly exclusively, to global clone ECII, with 53 % of them forming a genetically relatively homoge- neous group characterized by extensive resistance to antibiotics (susceptible only to col- istin), the presence of genes encoding ArmA a OXA-23 (resistance to all aminoglycosides and carbapenems) and spread in all locations. The in-depth epidemiological analysis of isolates from the city of Příbram and its vicinity indicated the regional spread of two strains, one of which belonged to the...