Diarrhea due to enteric pathogens is an important complication of advanced human immunodeficiency virus infection. Whereas numerous bacterial and parasitic agents have been implicated, the role of pathogenic enteric viruses is less clear. Stools from 153 human immunodeficiency virus seropositive men were tested by electrophoresis, enzyme-linked immunosorbent assay, and immune electron microscopy for the presence of rotaviruses (group A and non-group A), adenoviruses, and Norwalk agent. Virus was detected in 9% of the patients with acquired immunodeficiency syndrome, 3% of the patients with acquired immunodeficiency syndrome-related complex, and none of the seropositive men without these diagnoses. Virus detection was not more likely in stool from patients with diarrhea.