Background and Objectives: To evaluate the early and long-term results of surgical treatment of isolated mitral native and prosthetic valve infective endocarditis.Materials and Methods: All patients undergoing mitral valve repair or replacement for infective endocarditis at our institution between January 2001 and December 2021 were included in the study. The preoperative and postoperative characteristics and mortality of patients were retrospectively reviewed.Results:A total of 130 patients, 85 males and 45 females, with a median age of 61 ± 14 years, underwent surgery for isolated mitral valve endocarditis during the study period. There were 111 (85%) native and 19 (15%) prosthetic valve endocarditis cases. Fifty-one (39%) patients died during the follow-up, and the overall mean patient survival time was 11.8 ± 0.9 years. The mean survival time was better in patients with mitral native valve endocarditis compared to patients with prosthetic valve endocarditis (12.3 ± 0.9 years vs. 8 ± 1.4 years;p= 0.1), but the difference was not statistically significant. Patients who underwent mitral valve repair had a better survival rate compared to patients who had mitral valve replacement (14.8 ± 1.6 vs. 11.3 ± 1 years;p= 0.06); however, the difference was not statistically significant. Patients who underwent mitral valve replacement with a mechanical prosthesis had a significantly better survival rate compared to patients who received a biological prosthesis (15.6 ± 1.6 vs. 8.2 ± 0.8 years;p< 0.001). Patients aged ≤60 years had significantly better survival compared to patients aged >60 years (17.1 ± 1.1 vs. 8.2 ± 0.9;p< 0.001). Multivariate analysis showed that the patient’s age >60 years at the time of surgery was an independent risk factor for mortality, while mitral valve repair was a protective factor. Eight (7%) patients required reintervention. Freedom from reintervention was significantly higher in patients with mitral native valve endocarditis compared to patients with prosthetic valve endocarditis (19.3 ± 0.5 vs. 11.5 ± 1.7 years;p= 0.04).Conclusions: Surgery for mitral valve endocarditis is associated with considerable morbidity and mortality. The patient’s age at the time of surgery represents an independent risk factor for mortality. Mitral valve repair should be the preferred choice whenever possible in suitable patients affected by infective endocarditis.