Worm infections are found in livestock and can be transmitted to humans. Toxocara vitulorum is a worm species which commonly infected people. Cross-reaction among worms can generate false positive to establish helminthiasis diagnosis through antibody inspection. This study aimed to determine specific proteins that caused cross-reaction between Toxocara vitulorum antigen and anti-M. digitatus serum by using the western blot technique. In the present study, the whole worms extracted of T. vitulorum and M. digitatus have been used to make polyclonal antibodies from M. digitatus with Wistar rats as hosts. The cross-reaction between whole worm extract of T. vitulorum protein and anti-M. digitatus serum obtained 12 protein bands that each relative molecular mass (Mr) valued of 176, 124, 92, 68, 59, 47, 31, 29, 26, 16, 12, and 10 kDa. Cross-reaction occurred between T. vitulorum protein and anti-M. digitatus.