A cross-sectional study on suberosis was conducted to determine the prevalence of respiratory symptoms and the level of pulmonary function, and their relationships within job categories of exposure to cork dust, toluene diisocyanate (TDI) resin bonding and conidia, among cork workers. Exposure-response relationships, with confounders taken into account, showed specific associations between cork dust and chronic bronchitis, TDI and asthma, and conidia and symptoms of hypersensitivity pneumonitis. Workers exposed to these risk factors had reduced mean spirometric values. A significant correlation between a decrease in pulmonary function and length of exposure was found for the workers exposed to cork dust. These results strongly suggest that suberosis, as hitherto described, might in fact be comprised of three different diseases with different etiologic risk factors, ie, respiratory hypersensitivity from exposure to conidia, asthma from exposure to TDI, and chronic obstructive pulmonary disease from exposure cork dust.