Indwelling urinary catheters are placed in up to 25% of hospitalized patients and are a leading cause of hospital-acquired infection. Duration of catheterization is the dominant risk factor for hospital-acquired urinary tract infection. Physicians are often unaware that their patients have a urinary catheter, and these "forgotten" catheters are frequently unnecessary.A controlled trial, using a pretest-posttest design, was conducted on four hospital wards at an academic medical center. A simple written reminder was designed to aid the hospitalized patient's team in remembering that the patient had a urinary catheter. Two of the four wards were assigned to the intervention group, and two served as controls. A research nurse monitored the urethral catheter status of each patient daily.A total of 5,678 subjects were evaluated. After adjusting for age, sex, and length of stay, the average proportion of time patients were catheterized increased by 15.1% in the control group but decreased by 7.6% in the intervention group in the intention-to-treat analysis (p = .007). There was no significant difference in urethral recatheterizations between intervention and control groups. The hospital cost savings provided by the intervention offset the necessary costs of this nurse-based intervention. CONCLUSIORN: In the approximately 90% of U.S. hospitals currently without computerized order-entry systems, a written reminder should be considered as one method for improving the safety of hospitalized patients.