Background & Aim: The aim of this study was to investigate the antimicrobial effects of Zataria multiflora against some Acinetobacter baumannii strains isolated from clinical samples. Experimental: Twelve strains of Acinetobacter baumannii were isolated from referred patients in Zabol hospital. Essential oil of Zataria multifloraspecies was extracted using Clevenger device. Minimum Inhibitory Concentration (MIC) and Minimum Bacterial Concentration (MBC) of essential oil on mentioned bacteria were determined using micro dilution broth method at six different concentrations. Results: The results of this study showed that the lowest inhibitory concentration of essential oil against bacteria was 0.31 mg/ml, and only one strain of bacteria was inhibited. However, the highest inhibitory concentration was estimated 10 mg/ml. Recommended applications/industries: The results showed that the antimicrobial effects increased with increasing in essential oil concentration and the essence showed good antimicrobial activity even at low concentrations. With the use of essential oil of Zataria multiflora against bacterial pathogens, a good antimicrobial agent can be obtained without any side effects. تفاصيل المقالة