Background The Mediterranean food pattern (MeDiet) has been suggested to have beneficial effects on cardiovascular risk factors. Scarcity of assessment of this effect on large samples of patients at high risk is, however, observed. Our objective was to estimate the association between adherence to MeDiet and the prevalence of risk factors in 3204 asymptomatic high-risk patients. Design Cross-sectional assessment of baseline characteristics of participants in a primary prevention trial. Methods Participants were assessed by their usual primary-care physicians to ascertain the prevalence of diet-related cardiovascular risk factors (diabetes, hypertension, dyslipidemia, or obesity) using standard diagnostic criteria. A dietitian interviewed each participant to obtain a 14-point score measuring the degree of adherence to MeDiet. Results Adherence to MeDiet was inversely associated with individual risk factors and, above all, with the clustering of them. The multivariate adjusted odds ratio to present simultaneously the four risk factors for those above the median value of the MeDiet score was 0.67 (95% confidence interval: 0.53–0.85). The multivariate odds ratios for successive categories of adherence to MeDiet were 1 (ref.), 1.03, 0.85, 0.70 and 0.54 ( P for trend ≤0.001). Conclusion Following a MeDiet was inversely associated with the clustering of hypertension, diabetes, obesity, and hypercholesterolemia among high-risk patients.