BACKGROUND AND OBJECTIVES: We have intended to investigate the influence of the timing of invasive procedures on all-cause mortality, recurrent myocardial infarction (MI), re-hospitalization due to cardiac causes and left ventricular function over a 3-month period among patients with Non-ST-elevation myocardial infarction (NSTEMI). SUBJECTS AND METHODS: A total of 131 NSTEMI patients with moderate-high Thrombolysis in Myocardial Infarction risk scores, who had been admitted to our department between July 2011-December 2011 were included in our study. They had been randomized into 2 groups according to the timing of the percutaneous coronary intervention (PCI). Patient undergoing PCI in the first 24 hours of hospitalization were named the "Early Invasive Group" and those undergoing PCI between 24-72 hours of hospitalization were named the "Delayed Invasive Group". All patients were followed up for 3 months. RESULTS: Third month left ventricular ejection fraction (LVEF) values were higher in the early invasive group (59.9+/-6.0% vs. 54.1+/-8.7%; p<0.001). Recurrent MI rates were lower in the early invasive group (2.9% vs. 14.5%; p=0.016). Similarly, hospitalization rates due to cardiac events were lower in the early invasive group (8.7% vs. 30.6%; p=0.001). All cause mortality appeared to be lower in the early invasive group, although not to a statistically significant degree (0% vs. 4.8%; p=0.065). CONCLUSION: The early invasive strategy appears to be more effective for the reduction of recurrent MI, re-hospitalization due to cardiac events, and the preservation of 3rd month LVEF in patients with moderate-high risk NSTEMI when compared to a delayed invasive strategy.