Familial hypercholesterolemia is a common autosomal dominant condition characterised by increased low density lipoprotein cholesterol, tendon xanthomas and premature atherosclerosis. Ultrasonography is the diagnostic tool of choice for the detection of tendon xanthomas in the Achilles tendon, demonstrated by the presence of hypoechoeic nodules or an increase in the antero-posterior diameter. It can also be used in screening and clinical follow-up of patients with familial hypercholesterolemia.