Background and Objective: Ischemic heart disease (IHD) following atherosclerosis is the most common cause of cardiac deaths world wide. We aimed to investigate the pathologic features of atherosclerosis in non cardiac death cases to have an estimate of atherosclerosis prevalence in Mashad (North east of Iran). Patients and Methods : This descriptive (cross sectional) study was done, during October 2007 – March 2008, on 80 cadavers from 11 to 50 years old who had died of non cardiac causes and had no history of cardiac disease. After autopsy in forensic medical center, coronary arteries were removed and examined for atherosclerotic plaques. In case of a definite or suspicious lesion, microscopic slides were also prepared. Otherwise, three random slides from each branch of coronary arteries were studied by a pathologist. Results: We found that 73.1% of men and 61.5% of women had at least one fibrofatty or advanced plaque in major coronary arteries. Atherosclerosis in 41.8% of men and 30.8% of women was in advanced form. Frequency of advanced atherosclerotic plaques progressed with age reaching a maximum of 78.5% by the age of 41-50 years. In addition, prevalence of plaques suddenly increased after second decade of life. Atherosclerotic plaques were most commonly found in left anterior descending artery (60%) followed by right coronary (50%) and left circumflex (42.5%) arteries. Conclusion: This study showed an unexpectedly high prevalence of atherosclerosis in this population. It highlights the importance of cardiovascular risk factor screening from early ages of third decade.