Background: A newly emerged hypervirulent strain of Klebsiella pneumoniae has caused great concern globally; however, its molecular characteristics have been rarely reported in Iran.Objectives: The goal of this study was to detect the virulence determinants and serotypes of K. pneumoniae and to evaluate the association among selected virulence traits and blaCTX-M-15 gene in southeastern Iran.Methods: One hundred and three non-duplicate K. pneumoniae strains were isolated from clinical samples. The isolates were identified by standard bacteriological tests. Confirmed isolates were examined to detect a selection of virulence genes (wabG, rmpA and iucB) and serotypes (K1, K2, K5 and K20) by PCR. The isolates were studied foe the presence of beta-lactamase (blaCTX-M-15) gene. SPSS software (version 19.0) was used for data analysis.Results: Among the 103 K. pneumoniae isolates, 61 (59.2%) isolates were positive for wabG, 4 (3.9%) for iucB and 3 (2.9%) for rmpA genes. The presence of K20 in 3.9% (4/103) of the isolates represented the most prevalent. Only 3 (2.9%) isolates possessed the K1 serotype, while K2 and K5 serotypes were not detected in any isolate. The blaCTX-M-15 gene was detected in 47 (45.6%) isolates. blaCTX-M-15-positive isolates showed a higher prevalence of wabG among the studied isolates (P < 0.05).Conclusions: Our data indicate a correlation between presence of virulence gene and blaCTX-M-15 in K. pneumonia isolates. Further research should be undertaken to unravel aspects of both virulence factors and antibiotic resistance which may probably contribute to managing future spread of infectious diseases.