Background: Risk score systems (RSS) were designed to estimate the risk of cardiac events. Their ability to predict coronary atherosclerosis (CA) has not been established., Hypothesis: Risk score systems can predict presence of CA in patients without typical symptoms or ischemia. Because design of each RSS is different, their predictive value could also differ., Methods: A retrospective analysis was done on patients from a low-risk region referred for cardiac multislice computed tomography (MSCT). The sample included low- to intermediate-risk patients with nontypical chest pain and asymptomatic high-risk patients. Patients with documented ischemia were excluded. Three RSS were determined: Framingham Risk Score (FRS), Regicor (FRS calibrated for Spanish population), and Systematic Coronary Risk Evaluation (SCORE). Coronary arteries were investigated to determine calcium score and presence of protruding atheromas., Results: We analyzed 582 patients (53.8% male; mean age 51 ± 11.5 years). Their mean estimated risk was intermediate: 15.6 ± 10.4 by FRS, 6.3 ± 4.3 by Regicor, and 3.9 ± 4.1 by SCORE. The MSCT showed no CA in 38.8%, nonobstructive plaques in 28.7%, and obstructive ones in 32.5%. The ability of the RSS to predict CA was not significantly different, with moderate diagnostic value (areas under ROC curves, 0.72-0.65). The prevalence of CA was high in low-risk patients: 40%, 47%, and 53% in FRS, Regicor, and SCORE low-risk patients, respectively., Conclusions: Risk score systems have only moderate diagnostic value to predict presence of CA, without significant differences among them. Coronary artery disease is highly prevalent in patients considered low risk., (© 2016 Wiley Periodicals, Inc.)