Rats with ventromedial hypothalamic lesions displayed a reduced sensitivity to dilute (5 or 7%) glucose solutions. The lesioned animals were less responsive to the food suppressive effects of glucose ingestion, and they drank less dilute glucose when food deprived compared to controls. The VMH lesioned rats, on the other hand, appeared normally sensitive to concentrated (20 or 33%) glucose solutions. They suppressed their feeding in response to glucose intubation, and they consumed more concentrated glucose solution than did controls, which is consistent with the hyperphagia effects of the lesions. The nature of the neural impairment responsible for these lesion effects is discussed.