Some strains of Acinetobacter which show multiple-drug resistance have produced therapeutic difficulties in worldwide. This is also a new problem in Iran. The purpose of current study was to define the antimicrobial susceptibility patterns and prevalence of bla_kpc gene in Acinetobacter baumannii isolates which had been isolated from patient in Tehran- Iran. This study was performed on 70 isolates of Acinetobacter which were isolated from patients. After identification of isolates in species level using cultural and biochemical methods, the susceptibility tests were carried out on 50 isolates of A. baumannii using disk diffusion method. Then isolates were considered for presence of bla_kpc gene by PCR. In this study 50 isolates of A. baumannii and 20 isolates of Acinetobacter lwoffii were isolated from patients. More than 55% of isolates showed multiple-drug resistance and also above 40% resistance to imipeneme and meropeneme was recorded. The MIC of isolates which were resistant to carbapenemes was above 32 µg/ml. The PCR results showed that 8 cases (16%) of isolates had bla_kpc gene which most of them had been isolated from patients who were hospitalized in the ICU. Carbapenem and multiple-drug resistant A. baumannii is expanding in Iran and it is considered as an important hazard for hospitalized patients. Moreover regarding to existence of bla_kpc gene in this bacterium and possibility of transformation of these genes to the other bacteria, reconsideration in antibiotics consumption patterns and more attention to nosocomial infections control criteria are inevitable.