Left atrial (LA) reverse remodeling occurs after transcatheter mitral valve repair, but additional data are needed about changes in LA function. Changes in LA stiffness in patients undergoing MitraClip implantation were evaluated. Baseline, procedural, and 30-day follow-up clinical and imaging data of patients undergoing MitraClip were reviewed. LA operating chamber stiffness was calculated as the ratio of systolic change in LA pressure to LA systolic strain and to stroke volume. Matched preprocedure and postprocedure LA strain analyses were performed in 35 patients, 21 with primary and 14 with functional mitral regurgitation (MR). Procedural success occurred in 34 of 35 cases with significant improvement of all invasive hemodynamic parameters. LA operating chamber stiffness decreased significantly in the overall population (p <0.001). At follow-up, sustained improvement in MR severity occurred, together with left ventricular (LV) and LA reverse remodeling. After MitraClip deployment, LA operating chamber stiffness showed a significant correlation with follow-up pulmonary artery systolic pressure, LV end systolic volume, and LV EF, irrespective of MR etiology (p <0.05). A significant inverse correlation was seen between change in LA operating chamber stiffness and improvement in 6-min walking distance. In conclusion, LA operating chamber stiffness decreases after MitraClip deployment, irrespective of MR etiology. It is related to pulmonary artery systolic pressure and functional status.