OBJECTIVE: The objective of this systematic review was to determine the effect of the timing of removal of indwelling urethral catheters (IUCs) on the duration to and volume of first void, length of hospitalization, number of patients developing urinary retention and requiring recatheterization, patient satisfaction, and the percentage of IUCs removed according to the scheduled time for removal. MATERIALS AND METHODS: Published and unpublished literature in English and other languages between January 1966 and June 2002, which compared the effects of the timing of removal of short-term indwelling urethral catheters on patient outcomes, was systematically reviewed using multiple electronic databases.To determine eligibility of the trials for inclusion in the review, assessment of methodologic quality and data extraction was undertaken independently by 2 reviewers and verified by a third reviewer. Odds ratio (OR) for dichotomous data and a weighted mean difference for continuous data were calculated with 95% confidence intervals (CI). Where synthesis was inappropriate, a narrative overview has been undertaken. RESULTS: Eight randomized controlled trials were eligible for this review. When IUCs were removed at midnight, the time to first void was significantly shorter (P = .012) after gynecologic surgery and significantly longer in patients after urologic surgery and procedures. Seven trials reported that the volume of the first void was greater in patients whose IUCs were removed late at night, and this was statistically significant in 4 trials.Patients who had their IUC removed at midnight were discharged from the hospital significantly (P < .00001) earlier than those who had their IUC removed in the morning, a finding that could result in potential cost savings for hospitals. CONCLUSION: Based on the limited available evidence, this article suggests benefits in terms of patient outcomes and reduction in the length of hospitalization after midnight removal of the IUCs. Further trials should be undertaken in wider settings and on specific groups of patients to enhance generalizability.