Diarrhea is still a prevalent health issue in HIV patients. Our objective was to characterize the different diarrheagenic E. coli (DEC) groups in stools from adult HIV patients. Cross sectional study: We enrolled HIV-positive and -negative patients with and without diarrhea from a tertiary-care center of Lima, Peru. Clinical data was recorded and a stool sample per patient was cultured. Multiplex PCR was used to detect different DECs. One hundred eighty-four participants were enrolled. The frequency of having at least one DEC was more common in HIV-positive than HIV-negative patients with diarrhea (42% versus 20%, P < 0.05). The enterotoxigenic E. coli (ETEC) was the most common DEC in patients with diarrhea, 13% in HIV patients. The diffusely adherent E. coli (DAEC) was only present in HIV positive patients with diarrhea (10.1%). Different types of DEC are frequent in stools from HIV-positive patients. Copyright © 2010 by The American Society of Tropical Medicine and Hygiene.