Background: The stenosis of the ostial left anterior descending artery represents one of the challenges for the interventional cardiologist. In contrast ostial stenosis of the left main trunk shows very good results after percutaneous interventions and implantation of drug-eluting stents. The indications for percutaneous transluminal coronary angioplasty (PTCA) of an ostial lesion correspond to the indications for treatment of all other lesions. Case: A-56-year-old woman was admitted to our hospital who was initially admitted in the intensive care unit for a severe acute chest pain. She had no coronary risk factors. No hormonal disorders were observed. Physical and laboratory examinations revealed that she had not suffered from syphilis or aortitis syndrome or any other inflammatory diseases. An electrocardiogram (ECG) was immediately performed and showed ST segment non elevation in the precordial leads (Figure 1) suggesting an acute anterior ST Non elevation myocardial infarction (NSTEMI). On coronary angiography, a 80% stenosis of the left coronary ostial stenosis was found, but no abnormality was found in other arterial trees. (Figure 2) The patient was diagnosed as having isolated coronary ostial stenosis. Conclusion: The patients are almost always middle aged woman with no coronary risk factors. , the involved coronary artery is the left main coronary artery, so its obstruction results in a serious condition. Therefore, though its pathogenesis remains to be determined, isolated left coronary ostial stenosis seems to be a distinct clinical entity.