To assess the prevalence of intestinal parasites in a cohort of human immunodeficiency virus (HIV)-infected adults in Cameroon, a cross-sectional study was conducted. Detection of parasites was performed in 181 stool samples from 154 HIV-infected patients with a mean CD4 cell count of 238 cells/mm(3). Only 35 patients (22%) were receiving antiretroviral therapy at the time of stool sampling, and 46 (29%) had diarrhea. Opportunistic protozoa were found in 15 patients (9.7%), 8 of whom (53%) had diarrhea. Enterocytozoon bieneusi was found in eight patients, C. parvum in six patients, and Isospora belli in three patients. All E. bieneusi isolates tested belonged to the same genotype. The prevalence of opportunistic protozoa among patients with CD4 cell counts less than 50/mm(3) was 32%.