The use, development, efficacy, and adverse effects of antimicrobial irrigation solutions for prevention and treatment of urinary tract infections in catheterized patients are reviewed. Bacteriuria occurs rapidly in catheter systems where urine is collected in an open vessel. With newer drainage systems, where the urine is collected in a closed catheter tubing-receptacle system, the incidence of bacteriuria is reduced substantially. Prophylactic continuous irrigation with various solutions has been demonstrated to be effective in decreasing the incidence of bacteriuria in open catheter drainage systems, especially for 10 days or less following catheter insertion. Prophylactic irrigation of closed catheter systems has not been demonstrated to prevent bacteriuria. Treatment of urinary tract in catheterized patients through use of an antifungal irrigation has been demonstrated to be effective in Candida cystitis. Prophylactic antimicrobial irrigations in closed catheter systems appears to be unnecessary and may promote infection with organisms resistant to the irrigating solution. Strict adherence to proper catheter care procedures is the most important factor in reducing catheter infection rates.