Background: The complications discussed with patients by surgeons prior to surgery vary, because no consensus on major complications exists. Such consensus may improve informed consent and shared decision-making. This study aimed to achieve consensus among vascular surgeons on which complications are considered ‘major’ and which ‘minor,’ following surgery for abdominal aortic aneurysm (AAA), carotid artery disease (CAD) and peripheral artery disease (PAD). Methods: Complications following vascular surgery were extracted from Cochrane reviews, national guidelines, and reporting standards. Vascular surgeons from Europe and North America rated complications as major or minor on five-point Likert scales via an electronic Delphi method. Consensus was reached if ≥ 80% of participants scored 1 or 2 (minor) or 4 or 5 (major). Results: Participants reached consensus on 9–12 major and 6–10 minor complications per disease. Myocardial infarction, stroke, renal failure and allergic reactions were considered to be major complications of all three diseases. All other major complications were treatment specific or dependent on disease severity, e.g., spinal cord ischemia, rupture following AAA repair, stroke for CAD or deep wound infection for PAD. Conclusion: Vascular surgeons reached international consensus on major and minor complications following AAA, CAD and PAD treatment. This consensus may be helpful in harmonizing the information patients receive and improving standardization of the informed consent procedure. Since major complications differed between diseases, consensus on disease-specific complications to be discussed with patients is necessary.