Introduction: Hemodynamically signifi cant mitral regurgitation (MR) occurs in up to 20-30% of patients with high-grade aortic stenosis (AC) indicated for transcatheter aortic valve implantation (TAVI). Despite the establishment of the method as a standard in the treatment of high-risk patients for surgery worldwide and the growing number of patients treated interventionally, behavior in concomitant signifi cant MR continues to be a diagnostic and therapeutic challenge. The decision to intervene on multiple valves must take into account the additional surgical risk of the combined procedures. Signifi cant MR is associated with a worse prognosis in both surgical and interventional treatment. With high operative risk and signifi cant MR, TAVI is a possible solution due to the proven reduction in severity in a signifi cant proportion of patients. The aim of this paper is to evaluate the impact of signifi cant secondary MR on mortality and rate change after TAVI. Material and methods: The article is a retrospective analysis of 50 patients with high-grade symptomatic aortic stenosis who underwent successful TAVI. Patients were followed for a period of 1 year and were divided into two major groups – no signifi cant MR (0.1 degree) and those with signifi cant secondary MR (≥ grade 2). Overall mortality, cardiovascular mortality, functional class of heart failure according to the NYHA classifi cation, ejection fraction and need for rehospitalizations weremonitored. Conclusions: Hemodynamically signifi cant secondary MR, concomitant high-grade AC before TAVI undergoes positive dynamics in a signifi cant proportion of patients postprocedurally and should be considered when deciding on a therapeutic strategy by the Heart team. The worsening of signifi cant secondary MI in the studied patients is associated with 30-day and one-year cardiovascular mortality and the need for rehospitalization, which is consistent with data that the prognosis is important not only the presence of signifi cant secondary MR, but its dynamics after TAVI.