BACKGROUND: Dairy consumption may be associated with a small but worthwhile reduction in cardiovascular disease risk, but results from epidemiological studies are inconsistent. The aim of the present study was to evaluate the association between dairy consumption and the prevalence of a first, non-fatal event of an acute coronary syndrome, in a Greek sample. DESIGN: Seven hundred male and 148 female patients with first event of an acute coronary syndrome and 1078 population-based controls, age and sex matched, were randomly selected. METHODS: Detailed information regarding their medical records, alcohol intake, physical activity and smoking habits was recorded. Nutritional habits were evaluated with a semi-quantitative food-frequency questionnaire. Multiple logistic regression analysis estimated the odds ratio of having acute coronary syndrome by level of dairy intake, after taking into account the effect of several confounders. RESULTS: An inverse relationship was observed between dairy products consumption and odds of having acute coronary syndrome. One portion increase in weekly dairy products intake was associated with 12% lower likelihood of having acute coronary syndrome, after controlling for various potential confounders (P<0.001). Cut-off analysis showed that 7.4 portions per week are the optimal consumption that benefits people from having acute coronary syndrome. CONCLUSIONS: Dairy consumption seems to offer significant protection against coronary heart disease, irrespective of various clinical, lifestyle and other characteristics of the participants.