Objective : Levosimendan is a new calcium sensitizer with inodilatory properties. There is growing clinical experience with levosimendan given to cardiac surgical patients. The aim of this study was to evaluate the effects of intra-operative use of different doses of levosimendan versus known inotrope e.g. adrenaline; in surgical patients with compromised left ventricular function.Design : Randomized controlled prospective study.Setting: Cairo university hospital.Participants : Patients undergoing cardiac surgery fulfilled our inclusion criteria.Methods : Thirty cardiac patients divided in three groups. group A (n=10) was received levosimendan as 30 mcg/ kg as loading dose over 5 min followed by 0.3 mcg/kg/min till the end of surgery, group B (n=10) was received levosimendan as 12 mcg/ kg as loading dose over 5 min followed by 0.05 mcg/kg/min till the end of surgery and control group (n=10) in which inotropic support e.g. adrenaline used only if needed.Results : Continuous levosimendan infusion increased cardiac index, stroke volume index significantly in both group A and B compared with control group. Pulmonary wedge pressure and mean arterial pressure systemic vascular resistance index significantly decreased in group A compared to both control group and group B which required vasoconstrictor support; noradrenaline (0.05µg/kg/min) in four patients. Pulmonary wedge pressure and mean arterial pressure systemic vascular resistance index showed modest change in group B compared control group. Heart rate showed significant increase in group A compared to control group and group B. Ejection fraction showed significant improvement in both group A and group B over control group but there was insignificantly changed between the two groups of levosimendan. These hemodynamic effects of levosimendan persisted postoperatively. Five patients in control group needed intropic support i.e. adrenaline. Conclusion : Levosimendan can be used for intraopertive inotropic support for cardiac surgical patients avoiding Side effects of conventional inotropes. Although higher doses may carry more favorable effects on hemodynamic variables but these changes were not significantly different from those with lower doses, in addition, higher doses may be associated with unfavorable effects which may need to be corrected for patient interest.