Three experiments were conducted to compare the role of lipoprotein lipase in fatty acid metabolism in chickens and turkeys. An initial experiment to determine the effect of fasting on the enzyme activity of chicken and turkey muscle and adipose tissues demonstrated that fasting decreased the lipoprotein lipase activity of adipose tissue, while increasing the enzyme activity of muscle tissue in chickens only. Quantitatively, turkey samples showed a greater enzyme activity in both muscle and adipose tissue than the chicken samples. In a second experiment both insulin and epinephrine added in vitro signifiacntly increased activity of lipoprotein lipase from chicken adipose tissue, but not from turkey adipose tissue. In a third experiment conducted to examine the effects of carbohydrate and fat feeding on lipoprotein lipase activity of chicken and turkey adipose tissue, fat feeding increased activity the greatest amount. In both species, refeeding, regardless of the energy source, produced a significant increase in the lipoprotein lipase activity of adipose tissue. Differences in lipoprotein lipase activity does not appear to be related to differences in rate of body fat deposition observed between broiler chickens and turkeys.