Nocturnal enuresis – or bed-wetting – is one of the most common chronic conditions of childhood. It has a significant effect on the quality of life of affected children and their families and is associated with several comorbidities, some of which resolve on successful treatment. The causes of this troublesome condition are explored and the principles of assessment and treatment are discussed with reference to National Institute for Health and Care Excellence guidance as well as research. Response to treatment resistance is considered and appropriate onward referral discussed.