Mitral valve lesion is one of most frequent a etiologies in cardiac surgery. Department of cardiac surgery of the St. Ioasaf Belgorod Regional Clinic executes average 485 operations per year. Of them 51–84 are operations on mitral valve. The mitral valve lesion etiologies are different. All cases of mitral valve corrections during the period 2015–2020 were chosen. The etiologies were: degenerative valve lesion, lesion, secondary to ischemic heart disease, infective endocarditis, chronic rheumatic heart disease, hypertrophic cardiomyopathy. During the chosen period were explored proportions of different etiological cases and their time changes. Were revised types of mitral valve correction, their frequencies and time changes. The interconnection between proportions of etiological cases, clinical gravity, combined lesions and changes in the prehospital care, methods of acute coronary syndrome treatment were explored.