Parasitism by Haemonchus contortus is one of the limiting factors for goat and sheep production around the world, especially in tropical regions, where the economic losses are more pronounced. Medicinal plant studies are being carried out to find an effective herbal medicine to control populations of this nematode and thus minimise the damage to the health and production of its hosts. In this way, the in vitro anthelmintic activity of the fixed seed oil of Carapa guianensis (andiroba) and Copaifera officinalis (copaiba) and the essential oil of Psidium guajava (guava) on eggs and larvae of H. contortus in goats was evaluated.