Abstract Aims There is no quality of life tool specifically developed for patients with severe aortic stenosis (AS) to assess how this chronic condition and its treatment affect patients. The Toronto Aortic Stenosis Quality of Life Questionnaire (TASQ) has been developed to overcome this gap. The results of the validation of the TASQ in patients undergoing treatment for severe AS are presented. Methods and results Prospective study at 10 centres in Europe and Canada, which enrolled 274 patients with severe symptomatic AS undergoing surgical or transcatheter aortic valve replacement. Mean TASQ score at baseline was 71.2 points and increased to 88.9 three months after aortic valve implantation (P