Nocturnal enuresis is a common problem of children during sleeping at preschool or school age. It may affect negatively the psychosocial development of children. Children with enuresis may have lower self-esteem and lower quality of life. There are three main factors of the pathophysiology of enuresis: high nocturnal urine production, nocturnal low bladder capacity or increased detrusor muscle activity, and arousal disorder. As pharmacological therapy for nocturnal enuresis, several medications including desmopressin, anticholinergics, imipramine have been used for a long time. As first-line therapy, desmopressin combined with anticholinergics has good response in primary monosymptomatic nocturnal enuresis. Because imipramine has serious and lethal cardiotoxic effect with overdosage, imipramine should be prescribed after EKG to rule out the conduction problem of heart.