The extracellular matrix phosphoprotein, Osteopontin (OPN) has been found in tissue fluids and organs, including the male reproductive tract. The vesicular gland and the ampullary region in the male reproductive system have been documented to secrete OPN, a 55 kDa fertility associated protein. The objective of this study was to quantify OPN and antioxidant concentrations in different epididymal sections in mongrel dogs. Current results showed a significantly (p<0.01) higher concentration of OPN in cauda epididymal fluid than in the caput. Glutathione peroxidase (GPx) and Catalalse (CAT) concentrations were also higher in the cauda epididymal segment than in the caput. To the author’s best knowledge, this is the first report on quantification of OPN levels in the epididymal fluid harvested from the different sections of epididymis. Further studies should focus on correlation and association of this protein from the different epididymal segments with seminal attributes.