Objective: The study assessed the anthelmintic activity of Artemisia absinthium ethanolic extract for controlling gastrointestinal nematodes in goats, both in vitro using infective larvae and in vivo in naturally infected goats under free-grazing conditions in the region of Ayacucho, Peru. Materials and Methods: For the in vitro assay, a larval motility inhibition test was performed on Trichostrongylus spp. infective larvae from goats using three different dilutions: 150, 175, and 200 mg/ml of the plant extract. In vivo efficacy was evaluated through the fecal egg count reduction test (FECRT), which was applied to 15 naturally infected Creole goats in one community. Animals were randomly assigned to 3 experimental groups and treated orally with 600 mg/kg of the plant extract. Fecal samples were collected directly from the rectum on days 0 (pre-treatment) and 7 and 15 post-treatment for e...