Pseudomonas aeruginosa is a common pathogen in a wide range of infections, from urinary tract infections to bacteremia. Intrinsic resistance to antimicrobial agents in this bacterium worsens the condition of the treatment of infections caused by it. The aim of this study was to investigate the antimicrobial effects of ethanol, methanol, and ethyl acetate Teucrium polium Extract and Citrullus colocynthis on a p. aeruginosa isolated from Zabol hospital. P. aeruginosa specimens were collected from Zabol city. Plant extracts were prepared using a rotary machine and the minimum inhibitory concentration and minimum trace concentration were determined by microdilution method. The lowest inhibitory concentration of methanolic extract of C. colocynthis against p. aeruginosa was 1.25 mg/ml while the lowest inhibitory concentration of ethyl acetate extract of C. colocynthis was 0.62 mg/ml, two strains were inhibited in this concentration and the highest inhibitory concentration was 5 mg, 6 strains of bacteria in this concentration has been restrained. The results of this study showed that watermelon extract of T. polium Extract and C. colocynthis have a significant antibacterial effect. Extract from this plant can be used to deal with specific pathogenic bacteria.