Background.A World Health Organization (WHO) case management approach has been used to identify and treat children with pneumonia worldwide since 1987. Many children are treated repeatedly: 23% of children with pneumonia in our rural Haitian district had met the WHO criteria on two or more occasions; but underlying disease in such children has not been systematically studied.Methods.We enrolled 103 children who had been diagnosed with pneumonia on 3 or more occasions by community health workers using WHO criteria. We compared them with 138 children similarly evaluated but never diagnosed with pneumonia, matching by health worker and age. We administered questionnaires to parents and performed complete physical examinations, tuberculin skin tests and serologic testing for HIV on all subjects and chest radiographs on case children.Results.Two percent of case children and 1.5% of controls had positive tuberculin skin test reactions. None of the children tested was HIV-seropositive. Ninety-four case children had normal baseline chest radiographs and three had focal infiltrates. A history of wheezing was reported for 79% of case children and 61% of controls (P= 0.002), and wheezing with exercise was reported for 36% and 22%, respectively (P= 0.02).Discussion.Most children in Haiti with recurrent pneumonia diagnosed by WHO criteria do not have evidence of tuberculosis, HIV infection or pulmonary anomalies, but they may be more likely to have asthma, and this should be considered as an alternative diagnosis. This information should help direct evaluation of such children in other settings and prompt further study of asthma in developing countries.