Our department has reported recent studies for nocturnal enuresis. The morning bladder capacity in enuretic children was smaller in the 3- and 4-year-old age range but larger in the 7-year and over age range than that in nonenuretic children. 15% of nonenuretic children showed nocturnal polyuria with nocturnal urination after complete awakening more than once per week. It was not likely from this evidence that an immature bladder capacity or nocturnal polyuria was the primary cause of enuresis. Patients with enuresis were classified into three types based on overnight simultaneous monitoring by electroencephalography and cystometry. The pathogenesis of enuresis type I and type IIa was a disturbance of awakening, while that of type IIb was a disturbance of bladder function not shown in the daytime but only at night. An original systematic therapeutic plan was established with the development of an original therapeutic machine primarily for enuresis type I.