The prevention and treatment of gastrointestinal nematodes based mainly on the use of antihelminthic drugs, producing increasingly the phenomenon of anthelmintic resistance (AR) in ruminants. The fecal egg reduction test (FECRT) is one of the main diagnostic method to detect AR and the resistant GIN are phenotipically classified. Molecular techniques are currently being studied to identify NGI resistant to different chemical groups. The objective of this work was to set up molecular tests to typify the main (GIN) identified as resistance by coprocultures when performing the FECRT in cattle herds.