The authors sought to determine whether exposure to molds, resulting from moisture damage in a school, was associated with increased respiratory symptoms and morbidity among schoolchildren and whether the renovation of this building resulted in a decrease in prevalence of respiratory symptoms and morbidity. The study was a follow-up (1-y interval) of children between the ages of 7 and 12 y from two elementary schools in a Finnish suburb. In addition to a questionnaire completed by the parents, the authors assessed the respiratory health of children by examining the health records of a local health center. In the cross-sectional study, the prevalence of symptoms and infections were higher in the exposed group, as were visits to a physician and use of antibiotics. The school was renovated, after which all prevalence decreased and no significant differences remained, except for visits to a physician (according to questionnaire responses). Therefore, moisture damage and exposure to molds increased the indoor air problems of schools and affected the respiratory health of children.