Acinetobacter baumannii causes serious hospital-acquired infections and has been positioned as a priority organism by the World Health Organization. This study includes 36 A. baumannii isolates from a children hospital recovered between March 2014 and May 2015 in Cochabamba. The majority of the isolates were recovered from blood cultures (n = 10, 31.3%) and respiratory samples (n = 11, 34.4%); 53% of the patients were younger than 1 month old. Most of these isolates (n = 30, 80.6%) were extremely drug resistant and 8.3% were multidrug resistant. The circulation of 2 predominant clones including 25 isolates was determined by pulsed-field gel electrophoresis; 9 of the isolates were considered sporadic strains. The isolates grouped in the predominant clones and 5 of the unrelated sporadic strains were single-locus variant or double locus variant of clonal complex (CC110), belonging to international clone 7; the rest of the isolates were single-locus variant or double locus variant of another clonal complex. All the carbapenem-resistant isolates (88.9%) carried the blaOXA-23-like in a similar structure to Tn2008 located on the chromosome, and the aac(3)-IIa gene was present in all the aminoglycoside-resistant isolates (86.1%). Strong biofilm producers were found among these isolates, being the strongest ones those recovered from the hospital environment, catheter, blood and cerebrospinal fluid (CSF) all of them belonged to the unrelated sporadic strains. The present study demonstrated the predominance and spread of closely related extremely drug-resistant A. baumannii isolates, what confers increasing risk to children and is of major concern because of the kind of infections and the lack of therapeutic alternatives to treat them.