A whole-diet approach has proven useful for characterising dietary exposure in cardiovascular epidemiology research. In our previous analyses, we found dietary patterns to be significant determinants of CVD risk factor levels among the Cardiovascular Risk in Young Finns cohort. We investigated the associations of major dietary patterns with carotid intima media thickness (IMT), a subclinical predictor of CVD, in healthy adults. The Young Finns Study is an ongoing, prospective cohort study with a 21-year follow-up to date. The subjects were children and adolescents at baseline in 1980 (aged 3–18 years), and all had reached adulthood by the latest follow-up in 2001 (aged 24–39 years). Complete dietary data from the years 1980, 1986 and 2001 and outcome data from the year 2001 were obtained from 785 subjects. The long-term average pattern score for a traditional dietary pattern (characterised by high consumption of rye, potatoes, butter, sausages, milk and coffee) was associated with IMT especially among subjects with a low score for the health-conscious dietary pattern (characterised by high consumption of vegetables, legumes and nuts, rye, tea, cheese and other dairy products). In multivariable regression analyses using long-term pattern scores as predictors, the traditional dietary pattern was independently associated with IMT in men (P < 0·01), but not in women (P = 0·66). Long-term adherence to traditional food choices seems to increase the risk of developing subclinical atherosclerosis among Finnish men.