The value of surgical therapy with or without ChT and/or RT for primary or recurrent thymic tumours with pleural involvement is not sufficiently defined yet, due to limitations in the available data. In this collaborative effort, members of the European Society of Thoracic Surgeons (ESTS) Thymic Working Group retrospectively collected data on patients undergoing thoracic surgical procedures for primary and recurrent thymic tumours with pleural involvement. The current work reflects the former and current practice patterns of European and Canadian thoracic surgery institutions treating TETs with pleural and/or pericardial involvement.