The Pseudomonas infection has been increased in incidence and suspected as a cause of opportunistic pathogen. Protease and elastase produced by Pseudomonas aeruginosa are reported to be closely associated with pathogenicity of Pseudomonas aeruginosa. We examined, in this work, the relationship between production of exoenzyme of Pseudomonas aeruginosa and susceptibility to antimicrobial agents in view of possible application to the management of Pseudomonas infection. 1. In 295 Pseudomonas aeruginosa isolated from clinical specimens, 34.6% were from pus, 20.7% from sputum, 15.6% from wound including burn sites and 12.9% from urine. 2. Distribution of protease and elastase production by clinically isolated Pseudomonas aeruginosa, showed that protease and elastase producing strains were 83.1%, protease producing strains were 7.5%, elastase producing strains were 2.0%, and non producing strains were 7.5%. 3. MIC(minimum inhibitory concentration) peak for tetracycline and chloramphenicol were observed at 25mcg/ml and 200mcg/ml respectively, but there were no Pseudomonas aeruginosa which correspond to MIC peak, 6.25mcg/ml. Gentamicin of aminoglycosides was highly susceptible to Pseudomonas aeruginosa clinically isolated from pus, sputum and wound sites, but susceptible to isolates from nasal discharge and urine. Regarding MIC peak of carbenicillin, 100mcg/ml, 81.8% of Pseudomonas aeruginosa were from urine, 54.8% from wound including burn sites, 52.7% from pus, and 50.8% from sputum. 4. Enzyme producing strains showed no susceptibility to kanamycine and carbenicillin at low concentration, but protease producing strains tend to resistant to antimicrobial agents.