In addition to virulence factors, antibiotic resistance has helped strains of Acinetobacter baumannii become one of the most common agents of hospital-acquired infections. In A. baumannii, carbapenem resistance is mainly mediated by carbapenemase. In this study, 144 strains of A. baumannii isolated from 9 hospitals in representing 3 regions of Vietnam were studied to detect the minimum inhibitory concentration (MIC) and find an association between carbapenem resistance levels and the appearance of some carbapenemase coding genes. Results: more than 70.8% of the isolated were resistant to 7/9 antibiotics tested; 83.3% strains were resistant to 3 carbapenem antibiotics with MIC₅₀, and MIC₉₀ values were 32-64 µg/ml and ≥64 µg/ml, respectively; 100% strains were susceptible to colistin (MIC₅₀=0.25 µg/ml and MIC₉₀=0.5 µg/ml). Strains with only bla_OXA-51 showed much lower rates of antibiotic resistance and MIC than those with ≥2 carbapenemase genes (p<0.01). 100% strains carrying bla_OXA-23 and bla_NDM-1 were resistant to carbapenem with very high MIC values. Conclusion: there is an association between carbapenem resistance and the appearance of gene bla_OXA-23 and bla_NDM-1. Colistin is the last resort for the treatment of multidrug-resistant A. baumannii.