Hospital discharge data can be useful in the identification of the more severe cases of both work- and nonwork-related chemical-related respiratory disease. The medical records of 329 patients hospitalized in Michigan in 1989 and 1990 for respiratory conditions resulting from chemical fumes and vapors (International Classification of Diseases diagnostic code 506) were reviewed to determine the location and etiology of the exposures. One-third of the discharges were work related. The most common exposures at work were to chlorine and sulfur dioxide and to industrial cleaning agents. Exposure to smoke from house fires and exposure to household cleaners were the most frequent causes of the nonwork-related discharges. Follow-up inspections at the work facilities where the hospitalized patients with work-related disease had become ill revealed that 61 of 261 (23.4%) fellow workers interviewed had new adult-onset asthma or were bothered at work by daily or weekly symptoms of shortness of breath, wheezing, or chest tightness. Nine of the 23 facilities inspected were cited for violating Occupational Safety and Health Administration standards.