Occupational hypersensitivity pneumonitis (OHP) is an interstitial lung disease caused by sensitization to an inhaled antigen. Polyethylene terephthalate (PET) is mainly used for disposable beverage bottles. A clinical case of hypersensitivity pneumonitis (HP) in a 66-year-old patient in the follow-up as a worker formerly exposed to asbestos is presented. At the first visit in 2012 a diagnosis of asbestosis and pleural plaques was formulated. In 2017 the high resolution computed tomography was performed demonstrating a slight progression of the pulmonary fibrosis, while physical examinations revealed inspiratory crackles on auscultation, and lung function tests showed a decreased diffusing capacity for carbon monoxide. The radiological and histological pictures were compatible with HP. From 1992 to 2013 the patient worked in a chemical company that produced PET for disposable beverage bottles. A diagnosis of OHP was made, and the most likely causative agents were terephthalic acid and dimethyl terephthalate. To the best of the authors’ knowledge, this is the first report of an OHP case in PET production. Int J Occup Med Environ Health. 2020;33(1):119–23