Background and Aim: Pseudomonas aeruginosa is an important cause of opportunistic infections. Infection caused by Pseudomonas aeruginosa is often severe and threatening, and is difficult to treat due to its limited susceptibility to antimicrobial agents and resistance to treatment. Therefore, the aim of this study was to identify the molecular identification of CTX-M-1 genes in the P. aeruginosa strains isolated from urinary tract infections in Zanjan hospitals. Materials and Methods: In this descriptive-analytical study of the study of 289 cases of urinary tract infection in Zanjan medical centers in 2019, 100 isolates of P. aeruginosa were identified by standard bacteriological methods. Antibiotic susceptibility of the isolates was determined by disk diffusion method and ESBL-producing isolates were identified by combined disk method. The bacterial DNA was then extracted and studied by PCR using specific gene primers. Results: The most resistant to ampicillin (73%) and tetracycline (49%) were the most sensitive to amikacin (90%) and nitrofurantoin (89%), respectively. A total of 35 samples were identified as the final ESBL producer. 29 specimens of Pseudomonas bacteria had the CTX-M1 gene. Conclusion: The genes studied in this study were all located on the chromosome of P. aeruginosa bacteria. Therefore, further investigation of ESBL genes such as CTX-M1 gene seems necessary to control this bacterium.