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. Primary neck carcinoma or metastases spreading in parapharyngeal and carotid spaces can involve the internal carotid artery and cause neurally mediated syncope with a clinical presentation like carotid sinus syndrome. We report the case of a 76-year-old man who suffered from recurrent syncope due to invasion of the right carotid sinus by metastases of a carcinoma of the esophagus, successfully treated by radiotherapy. In such cases, surgery, chemotherapy or radiotherapy can be performed. Because syncope may be an early sign of neck or cervical cancer, the diagnostic approach of syncope in patients with a past history of cancer should include the possibility of neck tumor recurrence or metastasis and an oncologic workout should be considered.