Multidrug-resistant (MDR) and hypervirulent Klebsiella pneumoniae (hvKp) clones have become a major threat to global public health. The CG258 is considered a high-risk CG and the K. pneumoniae strains belonging to it are known to be often multi-resistant and to spread mainly in the hospital environment. This study aimed to characterize the antimicrobial resistance profile, virulence factors, and the clonal relationships among 13 K. pneumoniae strains belonging to CG258 from patients admitted to a tertiary hospital in Teresina, in the state of Piauí, northeastern Brazil. Ten strains were classified as MDR and three as extensively drug-resistant (XDR). Three different β-lactamase-encoding genes ( bla KPC , bla OXA-1- like , and bla CTX-M-Gp1) and six virulence genes ( fimH , ycfM , mrkD , entB , ybtS , and kfu ) were detected. Moreover, two hypermucoviscous K. pneumoniae strains and one capsular K-type 2 were found. Multilocus sequence typing analysis revealed 10 different sequence types (STs) (ST14, ST17, ST20, ST29, ST45, ST101, ST268, ST1800, ST3995, and ST3996) belonging to CG258, being two (ST3995 and ST3996) described for the first time in this study.