High-resolution B-mode ultrasound measurements of intima-media thickness (IMT) and plaque presence are useful to assess preclinical atherosclerosis. Normal carotid IMT values, but not normal femoral IMT values, have been reported in Spanish subjects. Our aim was to define the normality data of femoral ultrasound by sex and age. We studied 192 healthy subjects from a community cohort, 85 men and 107 women (mean age: 49 years; range: 20-81 years). We sonographically determined mean and maximum IMT in the far wall of the common femoral artery, plaque occurrence, and maximum plaque height. Reference values for femoral IMT, expressed as 25th, 50th, and 75th percentiles by sex and 5 age groups, were obtained. The 50th percentiles of mean IMT ranged from 0.50 to 1.04 mm in men in the age groups < or = 35 years and > or = 65 years, respectively. For women, corresponding IMT values ranged from 0.40 to 0.53 mm. IMT was positively related to age in both men (r = 0.44; p < 0.001) and women (r = 0.23; p = 0.019). From the regression equations of IMT versus age, the estimated yearly increase in IMT was 0.016 mm in men and 0.008 mm in women. More than 50% of men aged > or = 55 years and women aged > or = 65 years had plaques. Both IMT and plaque frequency are associated with age in men and women. Femoral IMT values in a Spanish community cohort are lower than those reported for geographical areas with higher cardiovascular risk, such as the Northern European countries and the US.