Background: Compromised ventricular function complicates the postoperative course after open heart surgery. Incidence of low-output syndrome (LOS) after cardiopulmonary bypass(CPB) is 30%. Vaso active therapy is required for weaning from bypass. Levosimendan is one of the new class of inodilator useful in refractory cardiac failure. Objective: The aim of this randomized control trial is to detect whether prophylactic levosimendan infusion is superior to milrinone in preserving better tissue perfusion, in decreasing complications related to low output syndromes and better hemodynamic control and to evaluate the efficacy of intravenous levosimendan infusion in decreasing the use of high dose of conventional inotropes and consequent prolonged hospitalization in open heart surgery patients with preoperative compromised ventricular function. Methods: Thirty consecutive patients with compromised cardiac function belongs to American Society of Anesthesiologists(ASA) physical status III who underwent open-heart surgery with CBP were randomly divided into two groups. Gr-L received levosimendan (loading dose of 12 μg/kg over 10 mins followed by infusion dose of (0.1 μg/kg /min ) and Gr-M received milrinone loading dose of 50 μg/kg over 10 mins followed by infusion dose of (0.5 μg/kg/ min )after anesthesia induction. Hemodynamic profile, mixed or central venous oxygen saturation (SVO2, SCVO2) which are surrogate markers for cardiac output, tissue perfusion were recorded, and blood obtained for troponin level. Results: SVO2 and SCVO2 were significantly higher in Gr L versus Gr M. Postoperative troponin-I concentrations, need of other inotropes incidence of arrhythmia, re-intubation, Intensive care unit(ICU) stay and hospital stay were significantly decreased in Gr L. Conclusion: Prophylactic levosimendan infusion maintains better hemodynamic control, tissue perfusion, myocardial protection and lesser complications in patients with compromised ventricular function.