Introduction. The optimal revascularization strategy for unprotected left main coronary disease (ULMCD) is the subject of ongoing debate and patients with ULMCD still represent a challenge for interventionalist, especially in the setting of an acute coronary syndome (ACS). Case report. We presented two cases of percutaneous treatment of ULMCD in the settings of ACS (ST Segment Myocardial Infarction and Non ST Segment Myocardial Infarction - STEMI and NSTEMI) in a catheterization laboratory without back-up of cardiosurgical department. Both patients were hemodynamically unstable with clinical signs of cardiogenic shock. Coronary angiography revealed left main thromobosis and using intra-aortic balloon pump as hemodynamic support primary angioplasty procedures were performed. Immediately after the procedures the patients hemodynamically improved and remained stable till discharge from hospital. Conclusion. Percutaneous coronary intervention (PCI) has become the most common strategy of revascularization in ACS patients with ULMCD and is generally preferred in patients with multiple comorbidities and/or in very unstable patients. In cases with no cardiosurgical departments PCI is an inevitable, bail-out, life saving procedure.