Objectives: To determine the short-term clinical effects of levosimendan in acute myocardial infarction (AMI) patients with myocardial stunning after emergency percutaneous coronary intervention (PCI). Methods: The study population consisted of 30 patients with AMI who received emergency PCI and satisfied the inclusion criteria. Levosimendan was given as a continuous infusion of 0.1 μg/kg/min for 24 h, and the remaining 10 patients received placebo treatment. The patients were observed with invasive haemodynamic monitoring and were evaluated biochemically and echocardiographically before and after the drug infusion. Results: Following treatment, biochemical indices (not including creatine kinase and its MB fraction) were significantly lower in the levosimendan group than in the placebo group. Meanwhile, left-ventricular (LV) end-systolic volume, mean pulmonary arterial pressure, pulmonary capillary wedge pressure and systemic vascular resistance were significantly reduced in the levosimendan group, whereas the early-to-late diastolic velocities ratio, LV ejection fraction, cardiac index and cardiac power index were increased. Troponin I levels were reduced and fewer stunned and infarction segments were observed in the patients treated with levosimendan. Conclusions: Levosimendan can significantly improve the myocardium function of patients with myocardial stunning after PCI.