We report a patient with motor neuron syndrome accompanying Sjögren's syndrome. The patient showed progressive quadriparesis and slurred speech, but neither sensory involvement nor detrusor dysfunction was noted. EMG displayed upper and lower motor neuron damage. Although sicca symptom was not too obvious, parotid gland and submandibular gland ultrasound showed diffuse lesions. The Laboratory tests also displayed markedly elevated levels of Anti-SSA and anti-Ro 52 antibody. After a course of intravenous immunoglobulin therapy and 3 weeks of comprehensive rehabilitation, the patient showed significant improvements in terms of speech, muscle strength, trunk balance, posture control and ability of daily life. We suggested that the possibility of autoimmune-mediated motor neuron damage should be considered, when patients with motor neuron syndrome accompanying Sjögren's syndrome. And they may benefit from intravenous immunoglobulin therapy and appropriate rehabilitation.