The magnitude of intestinal parasitic infection in human immunodeficiency virus (HIV) /AIDS patients requires careful consideration in the developing world. However, there have been very few studies addressing this issue in Ethiopia. This study was conducted to determine the prevalence of intestinal parasitic infection in HIV/AIDS patients at Jimma Hospital, Southwest Ethiopia, between January and February 2002. Stool specimens from HIV/AIDS patients and control groups were screened for intestinal parasitic infections using direct and formalin-ether sedimentation concentration methods. Out of 78 HIV/AIDS patients, 52.6% (41/78), and out of 26 HIV-negative individuals, 42.3% (11/26), were infected with one or more types of intestinal protozoa and/or helminthes. The parasites detected among HIV/AIDS patients included Ascaris lumbricoides (30.8%), Blastocystis spp. (14.1%), Entamoeba histolytica (10.3%), Trichuris trichiura (6.4%), Strongyloides stercoralis (5.1%), Giardia lamblia (3.8%), Schistosoma mansoni (2.5%), hookworm species (2.5%), and Taenia spp. (1.3%). Multiple infections were more common among HIV/AIDS patients. Blastocystis spp. were found to be significantly higher in HIV/AIDS patients than in controls (P < 0.05). The magnitude of intestinal parasitic infection was high both in HIV/AIDS patients and in controls. Routine examinations of stool samples for parasites would significantly benefit the HIV-infected and uninfected individuals by contributing to reduce morbidity.