BACKGROUND Carotid intimal medial thickening (c-IMT) is an established surrogate marker for atherosclerosis. There have been sporadic reports about an increase of c-IMT on the left carotid artery among populations with a mean age of +/-50 years. OBJECTIVE The purpose of this study was to evaluate whether there is a difference in c-IMT between the two carotid arteries in a group of young healthy adults. METHODS Ninety-eight healthy adults with a mean age of 28 years underwent blood tests to evaluate various cardiovascular risk factors as well as automated ultrasonic measurements of their c-IMT on both carotid arteries. RESULTS No significant difference was noted between c-IMT on both sides. In fact, the c-IMT on left carotid artery in men (n = 52) was 0.625 +/- 0.078 mm while on the right carotid it was 0.626 +/- 0.075 mm (P = 0.884). The values for women (n = 46) were 0.615 +/- 0.059 mm and for men 0.622 +/- 0.0618 mm (P = 0.582), respectively. CONCLUSIONS As opposed to a noted increase of c-IMT on the left carotid artery in older individuals, we did not find this difference in a group of young and relatively healthy adults. It is possible that if mechanical stress forces contribute to an enhanced left c-IMT, it takes a relatively long time to become evident.