Objectives: The purpose of the present study is to evaluate the impact of calcium score and the degree of coronary calcification at the target lesion amenable for percutaneous coronary intervention (PCI) on the immediate technical and clinical outcome of the procedure. Methods: The present study was conducted on 50 patients (38 males, 12 females) who underwent elective MSCT and were referred to Percutaneous Coronary Intervention at International cardio scan center in the period from October 2010 till October 2012. Results: Treatment of calcified coronary stenosis with percutaneous transluminal coronary angioplasty is often associated with decreased success and an increased complication rate. Complications are primarily the result of severe dissections, with dissection planes frequently occurring at the edges of the calcified plaque, finally leading to restenosis. Conclusion: In this retrospective study of sample patients we demonstrated that percutaneous coronary intervention stenting of calcified coronary lesions had additional adverse clinical outcome, and the risks increased proportionally to the degree of calcification.