The EORTC Lung Cancer Group (LCG) is a multidisciplinary international group of experts performing clinical research in lung cancer since 1962. Originally, the group consisted mainly out of French and Belgian investigators and expanded gradually into a wide range of investigators from all European Union countries, as well as some investigators from Switzerland, Poland, Czech Republic, Egypt, Slovenia, South Africa, Peru, Brazil and Cyprus. Despite the wide collaboration, it remains a difficult task to perform high quality large clinical research trials to answer important scientific questions in the treatment of lung cancer. For this reason, the EORTC Lung Cancer Group has invested a lot of efforts in promoting worldwide, randomised phase III studies in collaboration with other Groups. Furthermore, the LCG promotes small phase II trials of new drugs or treatments for lung cancer and stimulates the investigation of new strategies and treatments for rare intrathoracic malignancies.