The purpose of this experiment was to study the possible anthelmintic activity of papaya latex (Carica papaya) against Heligmosomoides polygyrus in experimentally infected mice. Five groups of BALB/C mice were infected with 100 Heligmosomoides polygyrus infective larvae/mouse. After patency (day 22) four groups of mice (groups B, C, D and E) were given papaya latex suspended in water at dose levels of 2, 4, 6 and 8 g of papaya latex/kg body weight, respectively. One group of mice (group A) served as non-treated controls. All animals were necropsied on day 25, i.e. 3 days after treatment, for post-mortem worm counts. The papaya latex showed an antiparasitic efficacy of 55.5, 60.3, 67.9 and 84.5% in groups B, C, D and E, respectively. The results may suggest a potential role of papaya latex as an anthelmintic against patent intestinal nematodes of mammalian hosts.