Adult male rats fed either ground Purina Laboratory Chow or the same diet adulterated with 0.5% quinine hydrochloride were tested for feeding in response to the administration of 2-deoxy-D-glucose (2-DG). Three doses of 2-DG were used, 250, 500 and 750 mg/kg of body weight. During a six-hr test period, rats given ground Purina Laboratory Chow ate significantly more following intraperitoneal (IP) injections of 250 and 500 mg/kg of 2-DG than following IP injections of physiological saline. Food intake of animals given Purina Chow also increased after administration of 750 mg/kg of 2-DG but intake was not significantly different from that following saline injections. In contrast to rats maintained on the unadulterated diet, rats given quinine-adulterated chow did not increase intake over saline values during the six-hr test period following administration of 250 and 500 mg/kg of 2-DG, and actually decreased intake after injection of 750 mg/kg of 2-DG. Results are discussed with respect to the role of diet palatability in determining food intake in hungry animals.