Nocturnal enuresis (bedwetting) is a socially disruptive and stressful condition which affects around 15% to 20% of five year olds and up to 2% of adults. Although there is a high rate of spontaneous remission, the social, emotional and psychological costs can be great. Behavioural interventions for treating bedwetting are defined as interventions that require a behaviour or action by the child which promotes night dryness and includes strategies which reward that behaviour. Behavioural interventions are further divided into:(a) simple behavioural interventions - behaviours or actions that can be achieved by the child without great effort; and(b) complex behavioural interventions - multiple behavioural interventions which require greater effort by the child and parents to achieve, including enuresis alarm therapy.This review focuses on simple behavioural interventions.Simple behavioural interventions are often used as a first attempt to improve nocturnal enuresis and include reward systems such as star charts given for dry nights, lifting or waking the children at night to urinate, retention control training to enlarge bladder capacity (bladder training) and fluid restriction. Other treatments such as medications, complementary and miscellaneous interventions such as acupuncture, complex behavioural interventions and enuresis alarm therapy are considered elsewhere. To determine the effects of simple behavioural interventions in children with nocturnal enuresis.The following comparisons were made:1. simple behavioural interventions versus no active treatment;2. any single type of simple behavioural intervention versus another behavioural method (another simple behavioural intervention, enuresis alarm therapy or complex behavioural interventions);3. simple behavioural interventions versus drug treatment alone (including placebo drugs) or drug treatment in combination with other interventions. We searched the Cochrane Incontinence Group Specialised Trials Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE in process, and handsearching of journals and conference proceedings (searched 15 December 2011). The reference lists of relevant articles were also searched. All randomised or quasi-randomised trials of simple behavioural interventions for treating nocturnal enuresis in children up to the age of 16. Studies which included children with daytime urinary incontinence or children with organic conditions were also included in this review if the focus of the study was on nocturnal enuresis. Trials focused solely on daytime wetting and trials of adults with nocturnal enuresis were excluded. Two reviewers independently assessed the quality of the eligible trials and extracted data. Differences between reviewers were settled by discussion with a third reviewer. Sixteen trials met the inclusion criteria, involving 1643 children of whom 865 received a simple behavioural intervention. Within each comparison, outcomes were mostly addressed by single trials, precluding meta-analysis. The only exception was bladder training versus enuresis alarm therapy which included two studies and demonstrated that alarm therapy was superior to bladder training.In single small trials, rewards, lifting and waking and bladder training were each associated with significantly fewer wet nights, higher full response rates and lower relapse rates compared to controls. Simple behavioural interventions appeared to be less effective when compared with other known effective interventions (such as enuresis alarm therapy and drug therapies with imipramine and amitriptyline). However, the effect was not sustained at follow-up after completion of treatment for the drug therapies. Based on one small trial, cognitive therapy also appeared to be more effective than rewards. When one simple behavioural therapy was compared with another, there did not appear to be one therapy that was more effective than another. Simple behavioural methods may be superior to no active treatment but appear to be inferior to enuresis alarm therapy and some drug therapy (such as imipramine and amitriptyline). Simple behavioural therapies could be tried as first line treatment before considering enuresis alarm therapy or drug therapy, which may be more demanding and have adverse effects, although evidence supporting their efficacy is lacking.