The aim of the present study was to determine both susceptibility and resistance pattern among clinical isolates of Pseudomonas aeruginosa in order to make continuous monitoring to the action of antipseudomonal drug in Egypt and to initiate the treatment with the appropriate antibiotic to avoid failure of treatment due to resistance. A total of 104 clinical isolates were collected and identified as Pseudomonas aeruginosa from Mansoura University Hospitals. The isolates were tested for antimicrobial susceptibility against 10 different antibiotics by using disk diffusion method. Resistance rates for imipenem, piperacillin, amikacin, gentamicin and ciprofloxacin were found 19.23%, 20.19%, 24%, 26.92%, and 30.76%; respectively. Resistance rates to chloramphenicol, co-trimoxazole, ceftazidime and ceftriaxone were variable and reached up to 83.65%. Exceptionally all isolates were resistant to carbencillin (100%). Thirty-six (34.61%) of isolates were multi-drug resistant. Imipenem, piperacillin and amikacin were the most effective antimicrobial agents against Ps. aeruginosa clinical isolates. It is recommended by the health authority to limit the further increase of antimicrobial resistance among Ps. aeruginosa by declining the rational treatment regimen.