<ns3:p><ns3:bold>Introduction</ns3:bold>: Recent reports indicate the emergence of community-acquired pneumonia associated with K64-<ns3:italic>Klebsiella pneumoniae</ns3:italic>. Here, we identify the capsular types and sequence type of invasive and commensal <ns3:italic>K. pneumoniae</ns3:italic> isolates from Vietnam.</ns3:p><ns3:p> <ns3:bold>Methods</ns3:bold>: We included 93 <ns3:italic>K. pneumoniae</ns3:italic> isolates from patients hospitalized at the National Hospital for Tropical Diseases, Hanoi between 2007 and 2011; and 110 commensal isolates from throat swabs from healthy volunteers living in rural and urban Hanoi in 2012. We determined sequence types (STs) by multi-locus sequence typing (MLST) and capsule typing for seven K types by PCR. Antibiotic susceptibility testing was performed using disk diffusion.</ns3:p><ns3:p> <ns3:bold>Results</ns3:bold>: The most common detected capsule types were K1 (39/203, 19.2%, mainly ST23) and K2 (31/203, 15.3%, multiple STs: ST65, ST86, ST380). We found significantly more K2 isolates among invasive in comparison to commensal isolates (22.6% vs 9%, p = 0.01) but no significant difference was observed between invasive and commensal K1 isolates (14.5% vs 24.7%, p = 0.075). K64 with varying sequence types were predominantly seen among invasive <ns3:italic>K. pneumoniae </ns3:italic>(8 vs. 3) and were isolated from sepsis and meningitis patients. Among K64 isolates, one was carbapenem-resistant with ST799.</ns3:p><ns3:p> <ns3:bold>Conclusion</ns3:bold>: Our study confirms that capsule type K64 <ns3:italic>K. pneumoniae</ns3:italic> is associated with community-acquired invasive infections in Vietnam. Research is needed to unravel the mechanisms of virulence of capsule type K64 in both community and hospital settings.</ns3:p>