Background: Urinary catheters (UCs) with a closed urinary drainage system have been widely used in patients for many years. However, the frequency of replacing and operating these devices may be associated with catheter-associated urinary tract infection (CAUTI). Purpose: This study was designed to compare the incidence of CAUTI by replacement time (every 14 or ≥ 15 days) of the urinary drainage system. Methods: This 1-year prospective, nonrandomized controlled study was conducted in a major teaching hospital. The Transparent Reporting of Evaluations with Nonrandomized Designs Statement checklist was used. All of the patients with UCs were divided into two groups based on each patient's preference with regard to replacement time of the urinary drainage system. Results: Five hundred sixty-two patients were evaluated, and 341 patients with UCs were enrolled as participants in the study. In the per-protocol analysis, 16 patients (22.2%; 9.3 episodes/ 1,000 catheter-days) in the 14-day group and 15 patients (17.9%; relative risk = 1.24, 95% confidence interval [0.66, 2.34]) in the ≥ 15-day group (7.7 episodes/1,000 catheter-days; incidence density ratio 1.20, 95%confidence interval [0.60, 2.43]) had CAUTIs. A comparison of cleanliness within urinary bags showed no significant intergroup difference (p > .05). In the intention-to-treat analysis, the incidence of CAUTI between the two groups was also not significantly different (p > .05). Conclusions: No statistically significant difference in the incidence of CAUTI was identified between patients who used the 14-day replacement interval and those who used the ≥ 15-day replacement interval for their urinary drainage system.