A review of the literature concerning the use of enuresis alarms highlighted the lack of standardised definitions used to define enuresis and the insufficient understanding of the working mechanisms of alarms. Although first reported in 1904, enuresis alarms were not in routine use until the 1930's. Sensors in the bed or underwear, in conjunction with audible warning devices are the most common types of alarms. The alarm success rate of approximately 75% is independent of the type of alarm and there is a low relapse rate. In predicting alarm response, studies utilizing multivariate analysis techniques are superior to univariate techniques, but no one or combination of predictor variables is currently known to predict outcome accurately enough to alter standard clinical decision making. It is imperative that definitions are standardized and that study protocols are applied uniformly to well-defined populations that have a better potential response to enuresis alarms-the best intervention currently available.