Small but statistically significant differences in growth and food utilization were produced in the albino rat through gentling. When animals were gentled for 1 week preceding stress, no significant differences in growth, food utilization, carcass length or thyroid function could be found between gentled and non-gentled animals. If this initial gentling period was extended to 2 weeks, gentled-starved animals extended their growth and food utilization advantage over the non-gentled group, and showed a consistent trend toward lower thyroid function. Animals which were gentled for 2 weeks preceding electrical shock, lost their growth and food utilization over the non-gentled group, and both groups were markedly inferior to the non-shocked controls. Thyroid uptake measurements indicated that the basal metabolism of electrically shocked rats was increased over that of non-shocked animals, but no statistically significant differences existed between gentled and non-gentled groups.