We experienced four cases of transient enuresis in chronic schizophrenic patients following clozapine treatment. One case developed nocturnal enuresis only and the other three cases developed nocturnal enuresis combined with a dose of more than 300㎎/day. Nocturnal enuresis was managed by behavioral education, but for one case nocturnal enuresis was managed by reducing clozapine dosage. It is suggested that clozapine-related nocturnal enuresis is doserelated and tansient. Since Nocturnal enuresis may be embarassing for patients and not readily volunteered, it is helpful for the physician to inquire carefully about them