Background <p>Malignant neuroendocrine tumors of the cervical region are rare in cats, with reported differential diagnoses including thyroid and parathyroid carcinomas. Paragangliomas of the carotid body are rare tumors located at the bifurcation of the carotid artery that have been described in dogs and humans, but not in cats. Reports on treatment options for locally advanced neoplasia in this location in cats are limited.</p> Case presentation <p>This case report describes the clinical presentation, imaging findings, and treatment of a locally advanced cervical neuroendocrine tumor in a 14-year-old male castrated Main Coon with definitive-intent stereotactic body radiotherapy (SBRT). The tumor’s location enveloping the carotid artery, the imaging characteristics and growth pattern, the cytomorphologic features, including a negative Thyroid Transcription Factor-1 marker on cytology, the absence of a secretory phenotype, along with the presenting clinical signs, were supportive of the diagnosis of a paraganglioma of the carotid body. The treatment protocol consisted of 3 fractions of 10&#xa0;Gy (total 30&#xa0;Gy) delivered on a daily basis. A partial response was identified on physical exam 2 weeks following SBRT and at the follow up ultrasonographic scans at 15 and 24 months post-SBRT, with no local or systemic tumor progression noted for 755 days. The treatment was well tolerated with leukotrichia being the only radiation-induced side effect reported.</p> Conclusions <p>External beam radiotherapy, including SBRT, may be offered as a local treatment option for feline locally advanced head and neck neuroendocrine neoplasia.</p>