Tendon xanthomatosis often accompanies familial hypercholesterolaemia, but it can also occur in other pathologic states. Of the musculoskeletal system, the Achilles tendon is the most commonly effected tendon due to xanthomatosis. Although there are previous reports for flexor tendon involvement, to our knowledge there is no report in the English literature about bilateral hand extensor tendon xanthomatosis that causes restriction in the range of motion. The case that will be presented in this report is therefore unique.