Iatrogenic coronary artery disease following prosthetic valve implantation is a rare complication. This may result from mechanical injury in the intraoperative period. The use of balloon tip perfusion catheter presumably provides the initial insult with local vessel wall hypoxia. Once the diagnosis of coronary ostial stenosis is established, the procedure of choice is coronary artery bypass surgery. We report a case of a young lady who underwent aortic and mitral valves replacement for infective endocarditis. She was then diagnosed with ostial left main stem coronary stenosis after presenting with atypical symptoms. The patient eventually underwent coronary artery bypass surgery.