Abstract--1. The rate of 02 consumption (I;'o2) was measured in the salamanders Desmognathus ochrophaeus, Plethodon cinereus and Plethodon jordani to examine the interaction of repeated measurements, feeding, duration of equilibration to respirometers and duration of acclimation with thermal acclimation of metabolism.2. Measurements of the 1?o: of individual D. ochrophaeus for 8 consecutive days showed no consistent increase or decrease.3. Feeding resulted in a prolonged elevation in I7o2. The 17o~ of P. jordani increased by 77% on the day after feeding, did not begin to decline until 6 days after feeding, and still had not returned to initial levels after 11 days. 4. The post-feeding elevation in 17o2 can mimic thermal acclimation of metabolism. P. jordani that were fed immediately before acclimation to 5°C had a higher I7o2 than both unfed salamanders acclimated to 5°C and fed salamanders acclimated to 17.5°C. The Vo2 of the latter groups were similar.5. Acclimation to a warm temperature (17.5°C) required more than 1 week for completion. Significant metabolic acclimation occurred after 2-3 days.6. Individual D. ochrophaeus varied in both 17o: and the rate of thermal acclimation of metabolism.