This laboratory examined 2,158 stool specimens for intestinal parasites from 1,478 Southeast Asian refugees who immigrated to Massachusetts between September 1981 and April 1982. Seventy-five per cent of refugees harbored one or more of 20 different species of intestinal parasites. Multiple infections occurred in 49% of refugees. Twenty-one per cent had pathogenic protozoa, which are transmissible from person to person. Six per cent had nonpathogenic protozoa only. Entamoeba polecki, an ameba rarely seen in the United States, was found in 5% of refugees.