Introduction and objectives.The proportion of the ischemic heart disease (IHD) burden attributable to cardiovascular risk factors in Spain has traditionally been extrapolated from populations in other countries.The aim of this study was to estimate the IHD risk attributable to smoking, hypercolesterolemia, hypertensión, diabetes and excess weight using data from Studies carried out in the Spanish Population.Methods.Data on the prevalence of cardiovascular risk factors in the general population were obtained from a metaanalysis of 48 cross-sectional Studies carried out in Spain, and data on correponding prevalences among IHD patients were derived from PRIAMHO Ⅱ and PREVESE Ⅱ multicenter hospital registries.Crude and ajusted relative risks of IHD were obtained from follow-up data collected over 5 years in a primary-care cohort of 6124 adults without cardiovascular disease.The crude and adjusted population attributable fractions for various risk factors were calculated for both sexes combined and for men and women separately.Results.Among men, 42,5% (95% confidence interval CI] 6.8%-59.6%) of the adjusted incidence of IHD was attributable to overweight, 33.9% (95% CI 22.6%-41.=%) to smoking, 19.4 % (95% CI 8.2 %-26.5 %) to hypercolesterolemia, and 15.5% (95% CI 1.6%-24.6%) to hypertensión.Among women, 36.5% (95% CI-8.0%-56.3% ) of IHD cases were attributable to overweight, 24.8% (95% CI 12.0%-31.9%) to diabetes, and 20.1% (95% CI 6.1%-28.6%) to hypercholesterolemia Conclusions.The cardiovascular risk factors found to contribuye most to IHD in the Spanish population were excess weight in both sexes, followed by smoking in men.If our entire population was within the normal range of body mass index, ischemic heart disease cases would be reduced by 43% in men and 37% in women, regardless of age and the prevalence ofhypertensión, hypercolesterolemia and diabetes.The burden of coronary heart disease attributable to overweight may even increase in the near future, given the steady increase in the prevalence of obesity in Spain in recent years.Thus, this study strongly supports the importance being given to weight gain as a coronary risk factor and the need to implement preventive strategies to prevent the current epidemic of obesity.These results can be of usefulness in the planning and priorizitatión of actions for the prevention of coronary diseases at the Community level.