In a clinical setting, it is important to differentiate abnormal values that may be a normal change resulting from feeding and those that may be disease related. Such postprandial changes have been identified in mammalian and avian species. In the current study, pre- and postvalues for several routine biochemical analytes from penguins (Spheniscus demersus) were examined. Significant increases were found in uric acid, triglycerides, and bile acids (P < 0.001). Uric acid levels increased more than threefold. These data indicate that postprandial changes should be considered when interpreting abnormal biochemistry values in penguins.