Background:  We characterized by immunoblotting the antigenicity of the most frequent fungi colonizing cork during its industrial processing, Penicillium glabrum and Chrysonilia sitophila. Penicillium glabrum is the main causative agent of Suberosis, a hypersensitivity pneumonitis of cork workers. Chrysonilia sitophila induces both IgE sensitization and occupational asthma in the wood processing industry.Methods:  Serum‐specific IgG, IgG4 and IgE to P. glabrum and C. sitophila from nine cork workers with hypersensitivity pneumonitis (HP) and seven with asthma (four with occupational asthma) were analysed by immunoblotting.Results:  Both HP and asthmatic patients’ sera showed immunoreactivity to several proteins resolved in the specific immunoblot strips. The frequency of specific IgG recognition to 12–13.5 and 33 kDa proteins of P. glabrum was significantly higher in HP patients. The sera of HP patients had significantly higher specific IgG recognition to 16 and 51–55 kDa proteins of C. sitophila. There was no specific IgE recognition in the sera of HP or asthmatic patients to both fungi.Conclusions:  Different patterns of antibody reactivity to P. glabrum and C. sitophila are seen in cork workers with hypersensitivity pneumonitis or asthma. The 12–13.5 and 33 kDa proteins of P. glabrum and the 16 and 51–55 kDa proteins of C. sitophila may be major antigens in Suberosis.