The new WHO Classification of Lung and Pleural Tumours updates the previous proposal from 1981 and incorporates many new concepts that have developed since that time. A number of newly described lesions are included as well as current concepts in papillomas, adenomas, neuroendocrine tumours, adenocarcinomas, mesothelial tumours, and carcinomas with pleomorphic, sarcomatoid and sarcomatous features. The result is a comprehensive classification with detailed definitions and explantory notes illustrated by 150 high quality color photomicrographs that will promote uniformity in recording and reporting data nationally and internationally. The WHO panel consisted of 24 members from 14 countries giving a broad international input into this work.