OBJECTIVES: To evaluate the association between persistent use of statins and the risk of acute cardiovascular events among primary prevention patients in community settings. METHODS: A population-based retrospective cohort among 171,846 adults aged 45-75, with no history of any cardiovascular disease, who began statin therapy between 1998 and 2009. Proportion of days covered (PDC) with statins was measured by the number of dispensed prescriptions during follow-up period. Study endpoint was occurrence of a major cardiovascular event, which comprised myocardial infarction or performance of a cardiac revascularization procedure RESULTS: The fully adjusted survival analysis  indicated a significant negative association between persistence with statins and risk of incident cardiac events. The most persistent users (PDC >= 80%) had a hazard ratio of 0.62 (95% confidence interval: 0.58-0.67) compared to non-persistent users (PDC <20%). Similar results were found when analyses were limited to patients with more than 5 years of follow up. An interaction analysis between persistence and other factors detected a stronger risk reduction among diabetic males. CONCLUSIONS: This large and unselected community-based study supports the results of several randomized controlled trials regarding the beneficial effect of persistent statin therapy against cardiac events among primary prevention patients.