Objective: To evaluate the changes in ventricular repolarization parameters in preoperative and postoperative electrocardiograms (ECGs) of patients who underwent mitral valve repair (MVR) for mitral valve prolapse (MVP). Methods: Patients who underwent MVR due to MPV with severe mitral regurgitation were included in the study. A resting 12-lead ECG was recorded both preoperatively and 6 months postoperatively. QT, QTc, cQTd, JT, JTc, and Tp-e were measured; Tp-e/QT and Tp-e/QTc ratios were Results: The study included 53 patients (58.5% male), with a mean age of 52.7 +/- 13 years. The durations of PR, QRS, QT, cQT, cQTd, JT, cJT, and Tp-e were reduced significantly (p<0.001) six months after repair. Conclusions: The repolarization parameters changed after MVR surgery. Shortening of the QT, cQT, cQTd, JT, cJT, and Tp-e durations after the repair procedure may reduce the risk of sudden cardiac death, and arrhythmias in MVP.