AIM: The aim of this paper is to present a systematic review assessing the effectiveness of timed voiding for the management of urinary incontinence in adults. BACKGROUND: Despite the widespread use of systematic voiding programmes, their effectiveness is unclear, and the evidence for timed voiding has not been subject to rigorous and systematic evaluation. The impact on psychosocial factors and cost is also untested. The physiological basis for timed voiding is also poorly established. METHODS: The systematic review incorporated the methodology of the Cochrane Collaboration. All randomized or quasi-randomized controlled trials that addressed timed voiding for the management of urinary incontinence in adults were searched, appraised, analysed and summarized. The date of the latest search was 2002. Data were extracted independently and appraised according to the level of concealment of random allocation prior to formal entry; few and identifiable withdrawals and dropouts and an analysis based on an intention to treat. The relative risk for dichotomous data was calculated with 95% confidence intervals. Where data were insufficient to support quantitative analysis, a narrative overview was undertaken. RESULTS: Two trials of timed voiding met the inclusion criteria. In both, timed voiding was combined with other strategies. Participants were predominantly cognitively and physically impaired older women who resided in nursing home settings. Within-group improvements for the intervention groups were reported for both trials. One trial additionally reported a statistically significant reduction in night-time incontinence for the intervention group. The quality of the trials was modest and interpretation was limited by the potential for bias associated with inadequate concealment, missing data and no analysis by intention to treat. CONCLUSION: Terms used to describe voiding programmes that involve a fixed interval of voiding are variable. No conclusions can be drawn at this point about the effectiveness of timed voiding for the management of urinary incontinence in adults.