Adult and immature rictulariid nematodes were recovered at necropsy from the small intestine of an adult slow loris, Nycticebus coucang, from the Milwaukee County Zoo in Wisconsin. The lumen of the entire small intestine was packed with more than 100 nematodes, the intestinal wall appeared thickened and the mucosal surface contained numerous petechial hemorrhagic foci. The cause of death was diagnosed as a septicemia and possible lupus erythematosis.