We report the case of a 65-year-old man with non-Hodgkin's lymphoma (NHL) not only in the brachial plexus but also in the central nervous system and parotid gland. He was referred to our hospital for evaluation of a right parotid mass. He also presented with bilateral facial palsy and paralysis of the left superior limb. Computed tomography scan and magnetic resonance imaging revealed mass lesions in the right parapharyngeal space, the deep lobe of the right parotid gland. and the left brachial plexus. A gallium-67 citrate scan demonstrated abnormal uptake in the left brachial plexus. These symptoms and lesions improved during steroid therapy. However, the symptoms worsened again after steroid therapy was discontinued. We performed a right parotidectomy to confirm the diagnosis. Histopathological study revealed NHL. He was treated with combination chemotherapy, and most of the lesions and symptoms, except bilateral facial palsy, improved. Despite follow-up treatment, a brain metastasis occured, and he died 16 months after the onset of symptoms.