To evaluate the use of ivermectin as a bird anthelmintic, 29 White Leghorn hens naturally infected with Ascaridia spp., Heterakis spp. and Capillaria spp. were treated with 0.2, 2 or 6 mg/kg intramuscularly or 0.2 or 0.8 mg/kg orally. Faecal samples were collected before treatment and at autopsy, 2, 6, or 16 days after treatment, when the intestines were also examined for helminths. None of the treatments gave satisfactory anthelmintic results.