Nocturnal enuresis (NE) is a common problem in childhood. About 20 % of five-year-olds wet the bed at least once a month. This often has a great impact on the children and their families. Still there are many who don’t seek help, and among those who do, only a few are offered the best documented treatment.NE has a multifactorial aetiology. It runs in families, but there has not been found one gene or one mode of inheritance. NE can represent a maturation delay, expressed by a delay in fine and gross fine motor skills, low birth weight and short stature. An explanatory model termed “the three systems” proposes NE results from an imbalance between nocturnal urine production, functional bladder capacity and the ability to arouse in response to a full bladder. Life events such as the parents divorce and other distressing experiences during childhood increases the risk of NE. Low socioeconomic status and other factors related to the family also affects the child’s risk of NE.Many treatment alternatives exist. The enuresis alarm has the best documented effect. Relapse can be reduced by a period of overlearning. Pharmacological treatment with desmopressin produces a more rapid reduction in wet nights, but most children relapse after treatment has ended. Imipramine is also proven effective, but is not recommended due to potentially serious side effects. Hypnotherapy has shown good results, but the studies are few and small.