Background: The pathophysiology of ischaemic mitral regurgitation (MR) is related to local and global left ventricular remodeling and papillary muscle dysfunction. An understanding of geometric alterations of mitral valve and left ventricle seems to be desirable in planning surgical treatment. The aim of this study was to compare the mitral deformation indices and left ventricle remodeling using the transthoracic echocardiography (TTE) and cardiovas- cular magnetic resonance (CMR) methods. Material and methods: 21 subjects (18 M, 3 F; mean age: 61±11.3 years) with coronary artery disease, ≥6 months after myocardial infarction, with di- agnosed functional mitral regurgitation (MR I-IV grade) underwent CMR and TTE within the period no longer than 5 days. TTE was performed with Vivid 7 GE Dimension, CMR - using Magnetom Sonata 1,5 T device. Cine gradient echo imaging was used for analysis. The parameters of left ventricle function were obtained manually using cardiac dedicated software Argus. The following parameters were analysed: mitral deformation indices as end- sys- tolic and end-diastolic mitral annular area, antero-posterior, antero-inferior, septo- lateral mitral annulus diameter in systole and in diastole, the coaptation height, the tenting area, mitral annulus diameter - anterior mitral leaflet lenght ratio and left ventricle remodeling parameters: left ventricular end-systolic diameter (LVESD), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic diam- eter (LVEDD), left ventricular end-diastolic volume (LVEDV), stroke volume (SV), ejection fraction (EF), sphericity index (SI), the wall motion score index (WMSI). Results: A strong correlation of the left ventricle remodeling parameters was observed between TTE and CMR methods. The strongest correlation was ob- served of LVESD (p=0.00001; r=0.91), EDV (p=0.00006; r=0.87), LVEDD (p=0.001; r=0.85), ESV (p=0.0004; r=0.82), WMSI (p=0.0003; r=0.82), sphe- ricity index (p=0.004; r=0.72) and a weaker correlation of EF (p=0.006; r=0.7), SV (p=0.026; r=0.59). Upon analysing mitral deformation parameters there was only detected a correlation between TTE and CMR regarding antero-inferior mitral annulus diameter in diastole (p=0.04; r=0.57), septo-lateral mitral annu- lus diameter in diastole (p=0.01; r=0.65) and tenting area (p=0.07; r=0.5). Conclusions: There were no significant differences in the assessment of left ventricle remodeling parameters between TTE and CMR. In evaluation of mitral complex deformation parameters CMR is more conve- nient than TTE because of its high spatial and temporal resolution.