This study included 57 adult female patients from intensive care unit, which were catheterized using silver coated silicone catheter, and 57 patients, who received normal catheter. Clinical and asymptomatic urinary tract infections (UTI) were ruled out. During the 14 days of catheterization silver coated silicone catheters were shown to have a prophylactic role with regard to development of clinically manifested and subclinical UTIs. However, the significant differences in the hydrophoby level, non-specific adhesion and biofilm formation of P. aeruginosa species, cultured from the urine, between the two groups during the catheterization period were absent. P. aeruginosa species, isolated from the patients, in whom silver-coated catheters were used, produced significantly less quantities of pyocyanin