A 74-year-old man presented with recurrent syncope 3 months after definitive surgery for hypopharyngeal cancer. The patient experienced dizziness and severe hypotension on the movement of the neck and head. CT revealed disease recurrence with masses encasing the left internal carotid artery. The patient was diagnosed with vasodepressor type of tumour-induced carotid sinus syndrome (tiCSS) and was referred for palliative intensity-modulated radiotherapy (IMRT). Ten days after the commencement of IMRT (25 Gy in five fractions), the symptoms of tiCSS improved, and there was no re-exacerbation of the symptoms till the patient died 56 days after the commencement of RT. Palliative IMRT was feasible and effective for recurrent malignant tiCSS. Given the fact that palliative IMRT is minimally invasive, this option could be widely adapted for patients with such poor general condition and prognosis.