Objective: Development of resistance against many of the commonly used antibiotics is an impetus for further efforts to search for new antimicrobial agents. The aim of the study was determined as antibacterial activity of silver nanoparticles produced by Plantago ovata seed extract against Pseudomonas aeruginosa. Methods: All 30 strains of P. aeruginosa wereisolated from isolates of the urinary tract infection of Hospital and the minimum inhibitory concentrations were distinguished by microdulition method. Results: The silver nanoparticles revealed Gaussian distributions with average diameter of 13 nm with some deviations.The result of plant extraction showed that the most MIC value was 100 ppm concentration, and 9 strains of pseudomonas were inhibited. Conclusion: Ag nanoparticles prepared by the effective cost reduction method described here which is greatly promising as antimicrobial agents. Applications of Ag nanoparticles based on these findings may lead to valuable discoveries in various fields such as medical devices and antimicrobial systems.