Aims : (i) To describe the methodology that was used to develop the new ATS /ERS clinical practice guidelines for diagnosing idiopathic pulmonary fibrosis (IPF); (ii) to discuss how to perform high-resolution CT (HRCT) in usual interstitial pneumonia and to describe its imaging pattern on HRCT; (iii) to describe the histopathological pattern of interstitial pneumonia; and (iv) to discuss the recommended diagnostic approach to IPF, with a particular focus on the important role of multidisciplinary discussions. Areas that require further attention will be discussed throughout the session.