Mixed aortic valve disease (MAVD) is defined as the combination of aortic valve stenosis (AS) and regurgitation (AR) and is relatively frequent, with a reported prevalence up to 20-30% of patients with aortic valve disease. Mortality of patients with moderate MAVD (coexistence of both moderate AS and moderate AR) is largely unknown, and therefore there are currently no guidelines-based indications for surgical or transcatheter intervention for these patients, which is considered only when one of the two lesions (AS or AR) becomes severe. Of note, indication for valve intervention in patients with isolated moderate AS is currently under investigation in several randomized clinical trials but only in the presence of relevant symptoms and signs of left ventricular (LV) dysfunction. One initial single-center study including 250 patients with moderate MAVD has evaluated outcomes in this specific subgroup and showed that patients with asymptomatic moderate MAVD and preserved left ventricular ejection fraction (LVEF) had similar adverse event rates (progression to New York Heart Association (NYHA) class III-IV, aortic valve intervention or cardiac death) to patients with isolated asymptomatic severe AS with preserved LVEF. However, the results were primarily driven by the progression of the NYHA Class and aortic valve replacement, and larger multi-center studies are advocated to confirm these findings, which may therefore identify a (new) group of high risk patients who should in principle benefit from an aortic valve intervention as much as patients with isolated severe AS. In addition, prognostic factors (including clinical and echocardiographic characteristics) for risk-stratification of patients with moderate MAVD have not been identified, which may help to refine the indication for valve intervention and optimize patient management.