Prosthesis-patient mismatch (PPM) is frequent following surgical aortic valve replacement (SAVR) and is associated with an increased risk of morbidity and mortality. Preventive strategies to avoid or minimise PPM should be implemented in patients who are at high risk (i.e., patients with a small aortic annulus or those undergoing a valve-in-valve procedure within a small surgical bioprosthesis) and/or vulnerable to PPM (i.e., depressed left ventricular [LV] systolic function, severe LV hypertrophy, concomitant mitral regurgitation, and paradoxical low-flow, low-gradient aortic stenosis). Recent studies suggest that transcatheter aortic valve replacement (TAVR) may be superior to SAVR for the prevention of PPM and associated adverse cardiac events, particularly in the subset of patients with a small (<21 mm) aortic annulus. However, further randomised studies are needed to confirm the potential superiority of TAVR for this purpose.