Carbapenems resistance in A. baumannii has been recorded over the years and emerged as a global threat in intensive care units and health-care facilities. In Iraq there is little attention about the molecular basis of the multidrug resistant of A.baumannii isolates in our hospitals, therefore the aims of the study are: Investigating the distribution of Multiple Drug Resistant (MDR) A. baumannii strains isolated from inpatients and surveying the presence of class D beta-lactamases genes (blaOXA-23-Like, blaOXA-24-Like, blaOXA- 51-Like and blaOXA-58-Like genes)in A. baumannii isolates and investigating their distribution among all clinical isolates. Analyzing the sequence of the blaOXA genes in order to detect the variations of the local isolates. The correlations of efflux pump genes with multidrug and carbapenems resistance. Measuring the gene expression of the most prevalent blaOXA genes.