Twenty adult apparently healthy Muscovy ducks Cairina moschata (10 males, 10 females) were used in a study to compare between sexes blood serum alanine aminotransferase (ALT), aspartate aminotransferase (ALT), alkaline phosphatase (ALP), total protein, albumin, and total bilirubin profiles using jugular venous blood. Comparative biometric measurements (weight, length, width and thickness) of their liver organs were also done. Total protein and albumin were significantly (P 0.05) by sex. The biometric measurements of the liver of Muscovy ducks according to sex were significantly (P < 0.05) higher in males than females. Liver biometric measurements according to lobation were significantly (P < 0.05) higher in the right lobe than in the left lobe, particularly, in terms of liver lobe weight and length of both sexes of ducks while liver lobe width and thickness were statistically similar (P > 0.05) in both sexes. Therefore, sex had a significant influence on serum total protein and albumin, as well as the biometric measurements of the liver of Muscovy ducks studied.