Background: The aim of this work was to isolate and identify soil microorganism capable of degrading MTBE.Methods: Samples collected from a wastewater MTBE plant of Mahshahr Petrochemical, Iran, and carried in screw-cap bottle to laboratory. Enrichment technique was used to isolate MTBE degrader. In enrichment studies, a Basal Salts Medium (BSM) was utilized which supplemented with MTBE compound in 6 concentration 50-800 ppm as sole source of carbon and energy. Contaminated soils also used as inoculums in enrichment steps.Results: According to this research, the consortium obtained from the wastewater of MTBE plant was performed by periodically adding MTBE over 3-month period. After several enrichment steps in BSM liquid medium containing MTBE as the sole carbon, of 800 ppm Concentration MTBE, a green- blue pigmented strain pw3, (i.e. Pseudomonas aeruginosa) which showed faster rate of MTBE removal, was isolated. It is worth nothing that this bacterium was capable to grow in MTBE concentration of 600 ppm as sole carbon and energy source. Pure culture was identified by colony morphology, Gram stain reaction and biochemical tests. Molecular identification study (PCR) to be continued.Conclusion: It is well known that MTBE-degrading bacteria play an important role in the elimination of MTBE in soil. Biodegradation is one of the promising techniques to reduce MTBE contaminated in the environment and MTBE degraders were reported as an efficient method used to degrade MTBE. The results of our research showed the potential pure bacterial cultures of Pseudomonas sp. For biodegradation of the MTBE-contaminated sites and confirmed the significant ecological role of bacteria in petroleum-polluted environments.