In an investigation of health complaints among employees of a water-damaged offıce building, the environment showed evidence of fungal contamination with the isolation of Stachybotrys chartarum in one of five bulk samples tested for fungal growth. In response, a public health offıcial recommended that employees be relocated from the building. Employees were subsequently moved to a different environment. A focused environmental investigation of microbial growth within the building followed, revealing moderate to high levels of fungi (Penicillium, Aspergillus versicolor) and bacteria in bulk and surface samples. S. chartarum was identified in one of 19 (5%) environmental samples using Czapek agar. A health survey of building occupants revealed a high prevalence of multiple symptoms, with a predominance of neurobehavioral and upper respiratory tract complaints. The majority of symptoms were significantly less prevalent after relocation from the water-damaged environment. The initial hypothesis that exposure to toxigenic fungi was responsible for the high prevalence of reported symptoms is diffıcult to investigate and confirm given the current limits of epidemiological knowledge regarding exposure to these organisms and building-related illness. Future interventions where mycotoxin exposure is suspected should emphasize the importance of risk assessment and risk communication.