A total of 50 environmental Pseudomonas aeruginosa isolates were collected from sewage and tap water in Baghdad, Iraq. The MICs of Cefotaxime and Ceftazidime were determined by using agar dilution method, The MIC ranged from 2 to 256 µg/ml.The results of antibiotic sensitivity test showed that among sewage P. aeruginosa isolates, resistance was observed most often to Ticarcillin (92%), Penicillin G (84%), Ceftazidime (12%), (8%) for each of Cefotaxime and Ticarcillin. On the other hand, all tap water isolates were sensitive to Ofloxacin and Levofloxacin, Except (5%) of isolates were resistant to Cefotaxime (25%) to Ceftazidime and (95%) to Ticarcillin. All isolates were tested for Extended-Spectrum β-Lactamase (ESBL) production. Ten isolates (20%) were found to be ESBL producers. All environmental P. aeruginosa isolates were screened for the presence of the blaCTX-M genes by application PCR, Only (30%) of them were positive for this test.