This study was performed in patients undergoing mitral valve replacement surgery to know the effectiveness of predictors of high VIS (Vasoactive Inotropic Score), leading to increased requirements of inotropic supports post operatively, prolonged mechanical ventilation and ICU stay with increased morbidity and mortality. This prospective observational study was carried in cardiac operation theatre in a tertiary care hospital. 60 patients undergoing MVR were included under the study. Patient and surgical factors pre operatively and requirement of VIS post operatively, with any morbidity or mortality were studied. We found that mean age >60 years, female gender were associated with high VIS. Preoperative factors such as comorbidities (COPD, Hypertension, DM), EF between30-50%, severe pulmonary hypertension, severity of MS, hepatic and renal dysfunction have predictive value. Also, the intraoperative factors such as mean CPB time, mean aortic clamp time and duration of ventilation can predict the requirement of high VIS. Patients who require high VIS during mitral valve replacement surgery were at risk for prolonged mechanical ventilation and an extended ICU stay. Hence, through our study, we concluded that patients with the above mentioned predictors should be treated with caution.