Nocturnal enuresis is a common problem that can be troubling for children and their families. Recent studies indicate that nocturnal enuresis is best regarded as a group of conditions with different etiologies. A genetic component is likely in many affected children. Research also indicates the possibility of two subtypes of patients with nocturnal enuresis: those with a functional bladder disorder and those with a maturational delay in nocturnal arginine vasopressin secretion. The evaluation of nocturnal enuresis requires a thorough history, a complete physical examination, and urinalysis. Treatment options include nonpharmacologic and pharmacologic measures. Continence training should be incorporated into the treatment regimen. Use of a bed-wetting alarm has the highest cure rate and the lowest relapse rate; however, some families may have difficulty with this treatment approach. Desmopressin and imipramine are the primary medications used to treat nocturnal enuresis, but both are associated with relatively high relapse rates.