Cork particles and fungus spores were commonly airborne in a cork factory in Portugal where some workers suffered from suberosis. Where cork was being handled and shaped, fungus spores were usually more common than cork particles. In a warehouse (fundão) where cork had moulded, up to 54×106 spores/m3 were general in the air, but workers handling the mouldy cork were exposed to as many as 128×106 spores/m3 Cork particles were most common close to cutting and sanding machines, but seldom exceeded 2×106 spores particles/m3. The most abundant species were Penicillium frequentans Westling, P. granulatum Bain., Aphanocladlum album (Preuss) W. Gains, Monilla sitophila (Mont.) Sacc. and Mucor plumbeus Bon. P. frequentans was common everywhere in the factory and mostly in units small enough to penetrate into alveoli.