Deep body temperatures were monitored with an implanted radiotelemetry device from 2 to 4 days prepartum to approximately 12 days postpartum in sows. The mean prepartum temperature of five normal sows was 38.6 degrees C, with a range of 38.3--38.9 degrees C. An increase in body temperature (1.4 degrees C) was associated with parturition. The increase in body temperature began about 12 hours before the first pig was born, peaked 1-2 hours after delivery of the last pig, and decreased during the first day postpartum but did not reach the prepartum values. Two days postpartum, the mean body temperature was about 1 degree C higher than it was during the prepartum period. The mean body temperature increased an average of 0.06 degrees C per day during the 12-day postpartum period. A diurnal pattern was evident in the body temperature variations.