Blood glucose and rectal temperatures were monitored in two strains of genetically obese mice (C57 BL/6J ob/ob) prior to and following intragastric ethanol administration in an attempt to relate the hypothermic response to ethanol to extracellular glucose concentration. In contrast to expectation, ethanol administration was typically associated with a hyperglycemia and a hypothermic response. In the ob/ob genotype, the hypothermic response was associated with pronounced hyperglycemia which was more emphatic in older animals. The data support the conclusion that ethanol-induced hypothermia is independent of blood glucose levels. In light of the known sensitivity of ob/ob mice to insulin, it is suggested further that the observed hypothermic response was not a function of the animals' ability to transport glucose into peripheral cells. The observed hyperglycemia of the obese animals was most likely stress-related.