An outbreak of allergic respiratory disease occurred in a new building that was characterized from initial occupancy by the presence of extensive visible mold (especially Aspergillus versicolor) on interior surfaces. Epidemiological study of the occupants of both the affected building and a comparison neighboring structure indicated high rates of respiratory and other symptoms among persons working in the affected building. Subsequent clinical evaluations of some persons occupying the building for up to five years identified several cases of building-related allergic respiratory disease, including asthma and hypersensitivity pneumonitis. Based on these findings, the building was evacuated before remediation began. The mycological goal of the three-year building restoration project was to reduce concentration of non-phylloplane fungi such as A. versicolor to the lowest feasible level. All visibly colonized materials in the building were discarded and all fine dust on interior surfaces was removed by vacuuming and/or damp wiping. A medical surveillance program utilizing serial self-reported questionnaires and readily available clinical evaluations was designed to monitor the health of building occupants after re-entry. Symptom rates just prior to building reentry were substantially lower than those found before evacuation and have remained unchanged after re-occupancy was completed. No new or recrudescent cases of illness are known to have occurred after building re-entry.