The association between the concentration of selenium in serum and risk factors for cardiovascular disease was studied in 467 apparently healthy men and women. The concentration of selenium in serum was significantly higher in men than in women (1.63 versus 1.51 mumol/L) (p less than 0.001). A statistically significant positive correlation between serum selenium concentration and total cholesterol was found in women, but not in men. No other statistically significant correlations were observed with the major risk factors for coronary heart disease. There were indications that high consumption of fish, coffee and bread were associated with increased serum selenium levels, but the differences did not reach statistical significance. Our findings suggest that serum selenium concentrations in the range 1.2-2.0 mumol/L are not associated with major risk factors for cardiovascular disease.