Primary nocturnal enuresis is common and has considerable psychological ramifications for children as they get older. It is a familial condition with complex inheritance patterns. The pathophysiology of the condition appears to be related to poor arousal from sleep, nocturia due to deficient vasopressin release in sleep and possibly a decrease in functional bladder capacity especially at night. The mainstay of treatment is the bed-wetting alarm. In recent years, desmopressin nasal spray has found a clinical niche as a short-term solution for children attending school camps or sleeping over at friends' houses and as treatment in the medium term for those unresponsive to treatment with a bed-wetting alarm. It may also be used as an adjunct to the use of the alarm. Treatment with imipramine is increasingly in disfavour because the relapse rate is unacceptably high and fatal overdose is a real possibility.