Radiation-induced neuropathic pain is a rare but devastating complication following cancer treatment. It is often progressive, refractory to conservative treatment, and sometimes irreversible. The exact mechanism of radiation-induced neuropathic pain is unknown, but it is associated with perineural fibrosis, atrophy, and ischemia. Systemic administration of local anesthetics is known to be effective for various acute and chronic painful diseases, such as neuropathic pain, as well as inflammatory and nociceptive pains. We report a patient with generalized radiation-induced neuropathic pain successfully treated with systemic lidocaine administration.