Body temperature is known to vary with environmental conditions, physical activity, and illness. There is also some suggestion that body temperature is higher in women than men, and higher in blacks than whites. This study was undertaken to determine if previously described differences in body temperature found in relatively uncontrolled settings associated with gender and race can be reproduced under carefully controlled conditions. Temperature was measured orally with calibrated mercury-in-glass thermometers in 92 healthy community-dwelling volunteers aged 64 years and older. Environmental conditions were carefully controlled and patients with physical conditions or medication regimes known to alter body temperature were excluded. The mean body temperature for all subjects was 36.86 degrees C +/- 0.23 degrees C. The means for white men and women did not differ significantly. There was a statistically significant difference between black and white women, with blacks having 0.13 degrees C higher temperature. We conclude that body temperature varies with race in older women. No significant gender-related difference in normal body temperature was found in these healthy elderly white men and women. Differences in body temperature between men and women found in younger patient populations may reflect the temperature elevations in women associated with menstruation.