The purpose of this study was to evaluate mitral regurgitation (MR) severity in patients undergoing transcatheter aortic valve replacement (TAVR) by standardized assessment of two-dimensional (2D) transthoracic echocardiography (TTE) and 1-year echocardiographic and clinical outcomes. Pre-and post-procedural TTE's of patients undergoing TAVR between 2008 and 2014 were analyzed. MR was graded according to current guidelines with a systematic and integrated approach. Longitudinal echocardiographic and clinical results were analyzed. Regression analysis was performed for change in MR grade at follow-up, using pre-determined variables and confounders. Pre-and post-procedural TTE were available in 213 subjects. Significant MR was seen in 22% at baseline and 15% at follow-up; MR grade ≥ 3 in < 10%. Severity did not change in 61%, and decreased in 20% of the patients. Overall, the prevalence of MR grades pre-and post TAVR was not significantly different, nor influenced by MR etiology or TAVR prosthesis type. However, higher MR grades and pacemaker absence at baseline, were independently correlated to more improvement of MR after TAVR. Regarding clinical outcomes, NYHA class improved in two-thirds of the patients, irrespective of the baseline MR grade. Overall survival was not significantly different amongst MR grades post-TAVR. MR grading using an systematic 2D echocardiographic approach in patients undergoing TAVR is feasible in clinical practice. Our data revealed a relatively frequent prevalence of significant MR (although grade ≥ 3 was scarce), overall no change in the MR grade at 1 year follow-up, improvement of functional NYHA class, and no significant differences in long-term survival amongst the post-TAVR MR grades.