The appearance of variations in the protein profile of Ostertagia ostertagi (Stiles, 1892) infective larvae (L3), which were induced by hypobiosis triggering factors, was evaluated by means of SDS-PAGE and densitometric analysts. Area integration analyses of their protein profiles was carried out between 66 and 77 kDa. Important quantitative variations were identified in the protein levels of the induced larvae, where a 5.25 fold increase compared to the control was observed. Two 75.4 and 70 kDa protein bands were found which exceeded the control profile by 4.5 and 44 fold, respectively. This fact suggests that the changes brought about in the process of hypobiosis induction are restricted. This work demonstrates changes at a molecular level corresponding with biological changes induced by conditions causing O. ostertagi hypobiosis.