Objectives: A multicentre evaluation of the frequency and nature of major intraoperative complications during video-assisted thoracoscopic (VATS) anatomical resections., Methods: Six European centres submitted their series of consecutive anatomical lung resections with the intention to treat by VATS. Conversions to thoracotomy, vascular injuries and major intraoperative complications were studied in relation to surgeons' experience. Major complications included immediate life-threatening complications (i.e. blood loss of more than 2 l), injury to proximal airway or other organs or those leading to unplanned additional anatomical resections. All cases were discussed by a panel and recommendations were drafted., Results: A total of 3076 patients were registered. Most resections (90%, n = 2763) were performed for bronchial carcinoma. There were 3 intraoperative deaths, including 1 after conversion for technical reasons. In-hospital mortality was 1.4% (n = 43). Conversion to open thoracotomy was observed in 5.5% (n = 170), of whom 21.8% (n = 37) were for oncological reasons, 29.4% (n = 50) for technical reasons and 48.8% (n = 83) for complications. Vascular injuries were reported in 2.9% (n = 88) patients and led to conversion in 2.2% (n = 70). In 1.5% (n = 46), major intraoperative complications were identified. These consisted of erroneous transection of bronchovascular structures (n = 9); injuries to gastrointestinal organs (n = 5) or proximal airway (n = 6); complications requiring additional unplanned major surgery (n = 9) or immediate life-threatening complications (n = 17). Twenty-three percent of the in-hospital mortalities (n = 10/43) were related to major intraoperative complications. Eight pneumonectomies (five intraoperative and three postoperative at 0.3%) were a consequence of a major complication. Surgeon's experience was related to non-oncological conversions, but not to vascular injuries or major complications in a multivariable logistic regression analysis., Conclusion: Major intraoperative complications during VATS anatomical lung resections are infrequent, seem not to be related to surgical experience but have an important impact on patient outcome. Constant awareness and a structured plan of action are of paramount importance to prevent them., (© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)