BACKGROUND: () is the most common cause of urinary tract infection (UTI) and typically treated with antibiotics. Unrestricted use of antibiotics may lead to the emergence of antibiotic-resistant bacteria. The present study aimed to isolate and characterize phages against from infected urine samples and to determine the lytic activity of phages against . METHODS: The present experimental study was conducted in the Laboratory of Bouali Sina Hospital (Sari, Iran) in May 2018. was identified from nine urine samples of patients with UTI using conventional microbiological methods. Bacteriophages were isolated from the infected urine specimens, and their lytic activity was determined using the spot test. The titer of the bacteriophages was measured using the double-layer agar technique. The morphology of the bacteriophages was revealed using transmission electron microscopy, and the latent time period and burst size were determined. Data were analyzed using the SPSS software package. RESULTS: was isolated from nine infected urine samples. The lytic activity of bacteriophages against was determined using the spot test by observing the formation of inhibition zones. Transmission electron microscopy showed phages belonging to the Myoviridae family. The latent time period was 20 minutes with a burst size of 1,200 plaque-forming unit (PFU) per infected cell. The results of the double-layer agar assay showed that the titer of bacteriophages was 20×10 PFU/mL. CONCLUSION: The bacteriophage was isolated from infected urine samples and characterized, and their lytic activity against was determined .