BACKGROUND Treatment protocols (including those for thoracic surgery) tend to be customized for individual hospitals. Procedural standardization is required to improve surgical tasks and patient outcomes. This study aimed to evaluate the effects of an initiative to standardize surgical tasks for efficient and safe performance. METHODS Hospitals associated with the Division of Chest Surgery of the Kyoto Prefectural University of Medicine held joint meetings involving their thoracic surgeons and operating room nurses between February 2011 and November 2012 to standardize surgical tasks. Operation times and blood loss were compared before and after standardization. RESULTS The implementation rate of standardized surgical tasks was 97%. The pre-operative (from entry to the operating room until commencement of surgery) and post-operative (from conclusion of surgery until departure from the operating room) times were significantly decreased after the standardization. When compared according to operative group (all thoracic surgery, lung lobectomy, and partial lung resection), operation times were shorter for all three groups; in addition, the amount of blood loss was lower in all three groups after standardization. A post-standardization survey showed improved morale among the meeting participants. CONCLUSIONS Interdisciplinary standardization of surgical tasks across institutions improved thoracic surgery tasks and surgical outcomes.