More than 20 patients with persistent poliovirus infections have been identified and reported to WHO. To date, almost all of these patients have had B-cell immune deficiency disorders. Since there are limited data on patients with HIV infection who have received oral poliovirus vaccine (OPV), we studied adults and children to determine if persons with acquired immunodeficiency due to HIV infection or cancer chemotherapy in a developing country setting had prolonged excretion of polioviruses. Stool samples from 94 HIV-infected children and 101 adults and 50 children surviving cancer in Guatemala City were cultured for polioviruses. No polioviruses were detected in any of the 195 persons with HIV infection or the 50 with cancer. The evidence from this and other studies indicates that the persistent poliovirus excretion in HIV-infected individuals is an unlikely event.