The relation of blood pressure, serum cholesterol, plasma fibrlnogen, and coagulation factor VIU with skinfold thickness at four sites (forearm, triceps, suprailiac, and subscapular) was examined in 2,948 white participants in the Northwick Park Heart Study. When considered separately, all four skinfolds were significantly associated with the four cardiovascular risk factors in males. Of the two limb skinfolds, forearm was consistently more strongly associated than triceps with the risk factors. The magnitude of the association between forearm skinfold and the risk factors was similar to that of the two trunk skinfolds, suprailiac and subscapular. Multiple regression analysis suggested an independent association of forearm skinfold with cholesterol and blood pressure In males when the other skinfolds were taken into account There was no consistent difference in the strength of the associations of the two trunk skinfolds with the risk factors. With the exception of systolic blood pressure, the associations between the cardiovascular risk factors and skinfold thickness in males were stronger at younger ages. In the case of females the findings were somewhat different The associations with the four risk factors were consistently stronger for the two trunk skinfolds than the limb skinfolds. Triceps was somewhat more strongly associated with the risk factors than forearm skinfold except for plasma fibrinogen. Thus there are sex differences in the association of the distribution of subcutaneous fat with cardiovascular risk factors.