Purpose: Major cardiovascular complications associated with noncardiac surgery represent a substantial population health problem for which there are no established efficacious and safe prophylactic interventions. Acetyl-salicylic acid (ASA) represents a promising intervention. The objective of this study was to determine surgeons' perioperative usage of ASA, and if they would enroll their patients in a perioperative ASA randomized controlled trial (RCT). Methods: Cross-sectional survey of all practicing Canadian general, orthopedic, and vascular surgeons. Our mailed, self-administered survey asked surgeons to consider only their patients who were at risk of a major perioperative cardiovascular complication. Results: The response rate was 906/1854 (49%). For patients taking ASA chronically, there was marked variability regarding ASA continuation prior to surgery amongst the general and orthopedic surgeons, whereas 76%of vascular surgeons continued ASA in 81- l000% of their patients. For patients not taking ASA chronically, approaches to starting ASA prior to surgery were variable amongst the vascular surgeons, whereas 70% of general and 82%o of orthopaedic surgeons did not start ASA. For patients taking ASA chronically, 73% of general surgeons, 70% of orthopaedic surgeons, and 36% of vascular surgeons would allow at least 40% of their patients to participate in a perioperative RCT comparing stopping versus continuing ASA. For patients not taking ASA chronically, most general (760%), orthopaedic (670%), and vascular (510%) surgeons would allow at least 40% of their patients to participate in a perioperative RCT comparing starting ASA versus placebo. Conclusion: This national survey demonstrates that perioperative ASA usage as reported by surgeons is variable, identifying the need for, and community interest in, a large penoperative ASA trial. © 2010 CIM.