OBJECTIVES: 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 (UTI). We have previously shown that physicians are often unaware that their patients have a urinary catheter in place, and that these "forgotten" catheters are frequently unnecessary. We sought to reduce the duration of urinary catheterization through the use of a written reminder placed on the patient's chart. METHODS: This before-and-after study with concurrent control groups occurred on four hospital wards at an academic medical center. We designed a simple written reminder that aided the hospitalized patient's team in remembering that their patient had a urinary catheter. Two of the four wards were assigned at random to the intervention group (where the reminder would be used); the other two wards served as controls. Bivariable analysis was followed by multivariable Poisson regression analyses using the number of catheter days as the dependent variable. RESULTS: A total of 5678 subjects were evaluated. The catheter reminder significantly reduced the proportion of days in which a catheter was present (0.32 for the control wards versus 0.13 for the intervention wards; p <0.001). Additionally, 41% of control patients had a catheter placed, compared to 18% of the patients on the intervention wards (p <0.001). In the Poisson analyses, the overall rate of days in which a catheter was present was reduced by 35% in the intervention wards (p <0.01). CONCLUSIONS: Catheter-related UTI is a common, costly, and morbid complication of hospitalization. Evidence from our study indicates that a written reminder that a patient has a urinary catheter decreases the rate of catheterization, and should thus be considered as one method for improving the safety of hospitalized patients.