Objectives Syncope is caused by a wide variety of disorders. Recurrent syncope as a complication of malignancy is uncommon and may be difficult to diagnose and to treat.

Methods In such cases, surgery, chemotherapy or radiotherapy can be performed, because syncope may be an early sign of pharynx cancer.

Results We report the case of a 48-year-old man who suffered from recurrent syncope due to invasion of the left carotid sinus by squamous cell carcinoma, successfully treated by radiotherapy and chemotherapy.

Conclusions The mechanism of syncope may be similar to that of idiopathic carotid sinus hypersensitivity, which consists of both cardioinhibitory and vasodepressor components in varying proportions.