AIMS: Lithuanian middle-aged men have a fourfold higher risk for coronary heart disease (CHD) mortality compared with Swedish men. In Sweden, CHD mortality is twice as high in blue- compared with white-collar workers. Whether the same risk factors that characterized Lithuanian men, compared with Swedish men, could be found in low socioeconomic groups within the cities was investigated. METHODS: The LiVicordia study compared both traditional and new possible risk factors for CHD among 150 50-year-old men in Linköping, Sweden and Vilnius, Lithuania. A comparison was made of the prevalence of these risk factors in high and low socioeconomic groups within the cities and, after controlling for the city, variations across socioeconomic groups in the total sample. RESULTS: Small differences were found in traditional risk factors between cities. However, Vilnius men were shorter, had lower serum levels of antioxidant vitamins, more psychosocial strain, and lower cortisol response to a standardized laboratory stress test. These characteristics were also found among men in low social classes in both cities. In linear regression models, short stature, low serum beta-carotene, low social integration, coping and self-esteem, high vital exhaustion, high baseline and low cortisol response to stress were related to low social class. CONCLUSIONS: The same set of risk factors, mainly relating to oxidative and psychosocial stress, that characterized Vilnius men was also found in men in low social classes within the cities. The results suggest that a common set of risk factors may help to explain health differences both between and within countries.