OBJECTIVES: Using statins in primary prevention is controversial given the low event rate and the difficulty to identify patients who really benefit. Coronary calcium score has been identified as a strong predictor of cardiovascular events, being recommended for risk stratification in intermediate risk individuals. This study aims to assess, from the Portuguese societal perspective, the cost-utility of determining coronary calcium score to guide the use of statins in individuals with elevated C-reactive protein and low LDL cholesterol. Three strategies are compared: no treatment, test and treat accordingly, and treat every patient with rosuvastatin 20mg. METHODS: A Markov model was developed to predict the occurrence of myocardial infarction, stroke, coronary revascularization and death. The model considers a lifetime horizon and a 3.5% discount rate. Clinical inputs were derived from the JUPITER trial and from a cohort of the MESA study fulfilling JUPITER inclusion criteria. Event costs were obtained from the literature. Rosuvastatin 20mg cost incorporates a discount to reflect the introduction of generics within a maximum of 5 years. RESULTS: Coronary calcium score determination and subsequent primary prevention in individuals with a score exceeding 100 dominates no treatment. Implementing primary prevention in those patients with positive score, and not just those with score above 100, implies a willingness to pay around 40,000€ per QALY. Finally, primary prevention in all individuals is not cost-effective when compared to primary prevention in those with positive calcium score as it is associated with a cost per QALY of more than 600,000€. CONCLUSIONS: Determination of coronary calcium score is cost-effective as it allows to identify those patients that will benefit most from primary prevention. Primary prevention in patients with calcium score greater than 100 should be implemented. The implementation of this strategy in other patients with positive calcium score depends on the willingness to pay for a QALY.