We present a case of extrinsic allergic alveolitis due to Penicillium frequentans exposure (suberosis) at a cork factory. Diagnosis was based on clinical history, a restrictive spirometric pattern, evidence of reticular-nodular lung infiltrates on the X-ray, intradermal skin tests with dual reaction and precipitins-positive serum samples in the presence of the P. frequentans fungus. Although the patient refused to submit to a specific bronchial challenge, two natural challenges occurred when he once again happened to handle wet cork after leaving his previous job. The literature referring to this disease is reviewed.