The authors present 2 cases in which urinary retention was related to supratentorial cortical lesions. These cases support the presence and function of a supratentorial center involved in control of the voiding reflex loop and indicate that lesions affecting this center can result in urinary retention rather than the syndrome of incontinence, urgency, and increased urinary frequency that is generally attributed to dysfunction of this system. In such cases, a clinical presentation of urinary retention in the absence of associated remarkable neurological deficits renders clinical evidence as a localizing sign.