A case of Horner's syndrome following a thyroidectomy for a benign mul
tinodular goiter is presented, the literature reviewed, and possible e
xplanations are discussed. Theories to explain this phenomenon include
: local trauma to the sympathetic chain during retraction of the carot
id sheath, anatomical variations which leave a patient susceptible to
damage to the sympathetic chain, postoperative hematoma compressing th
e sympathetic chain, and ischemic damage to the sympathetic chain.