Catheter-associated urinary tract infection (CAUTI) is one of the most common types of nosocomial infection. Reducing the duration of catheterization may be a key intervention in CAUTI prevention. We carried out a prospective time-sequence, non-randomized intervention study in five departments of our university hospital. We wished to determine the impact of daily reminders from nurses to physicians to remove unnecessary urinary catheters four days after insertion. The intervention significantly decreased the duration of catheterization in two out of five departments. The frequency of late CAUTI (LCAUTI) among catheterized patients in all five departments decreased from 10.6 to 1.1 per 100 patients (P = 0.003) and the incidence of LCAUTI decreased from 12.3 to 1.8 per 1000 catheter-days (P = 0.03). Logistic regression analysis showed that duration of catheterization and iterative catheter changes were associated with LCAUTI. This study demonstrates that a simple measure can reduce the frequency of LCAUTI.