1. 1. A time-course study of the effects of temperature on liver composition and hepatic lipogenic enzyme acitivity was carried out using immature male chicks maintained at 17 and 30°C. 2. 2. The main effects of maintaining birds at the lower temperature appeared to be associated with a marked increase in liver size. 3. 3. Temperature and length of exposure had a significant effect on liver composition. 4. 4. Temperature had no significant effect on the specific activities of citrate-cleavage enzyme, “malic” enzyme or isocitrate dehydrogenase although there was a substantial, if non-significant, increase in “malic” enzyme activity in birds maintained at 17°C. 5. 5. Temperature differences in the specific activity of hepatic citrate-cleavage enzyme could not be correlated with NADPH production from either “malic” enzyme or isocitrate dehydrogenase.