We present the results from three surveys conducted in 1988, 1991 and 1994 in Hedmark comparing risk factors for cardiovascular disease among men and women age 40-42 years. The data are compared with the results for persons in the same age group from the counties Vestfold, Rogaland and Nordland, and examined in the same periods. In 1991 the average levels of total cholesterol and infarction risk score were the same in Hedmark and the three other counties, but in 1994 Hedmark compared less favourably. While the mean levels of total cholesterol showed minimal difference between rural and urban municipalities in Hedmark, triglycerides and systolic blood pressure were higher in the rural areas. Adjustment of the results in Hedmark for lower attendance rate among unmarried, divorced and widowed persons in 1991 and 1994 than in 1988 does not affect other risk factors than smoking. We discuss possible explanations of the less favourable results and the implications for primary prevention of cardiovascular diseases.