A study by lavage of the digestive tract was made of 3 guanacos from the Province of Rio Negro and of 3 llamas from the Province of Jujuy, Argentina. In the stomach of the guanacos Ostertagia ostertagi and Trichostrongylus axei were found, in the small intestine Nematodirus spathiger, N. lanceolatus, N. filicollis, N. battus, Cooperia oncophora, C. mcmasteri, Trichostrongylus vitrinus and Capillaria sp. and in the large intestine of one guanaco a few Trichuris ovis and Skrjabinema ovis.