Analyses of 23 blood chemistry values were made in blood from 26 Antarctic penguins representing three different species Pygoscelis adeliae, Pygoscelis antarctica and Pygoscelis papua.2.2. Means, standard deviations and differences between species using multiple range test were obtained for each parameter investigated.3.3. Pygoscelis papua exhibits values of total protein and LDH greater than the other two penguins and lower values of cholinesterase, amylase and glucose. Mean concentration of urea was the lowest in the blood of Pygoscelis antarctica, and alkaline phosphatase mean value was the greatest in this species.4.4. Blood chemistry values in Pygoscelis penguins were essentially similar to those described in other bird groups. We have not found any apparent variation in penguins normal values that could be interpreted as an adaptation to Antarctic special environmental conditions.