Introduction: Intracranial tumors cause various neurological symptoms and neuropathic pain, which are often refractory to opioids. In some of these cases, the combination of Kampo medicines can be effective. Case: The case was a 44-year-old patient who underwent surgery for a suspected papilloma. After resection, pathological examination revealed squamous cell carcinoma, positive for margins, and then, the left intraorbital metastasis was observed. Due to the intracranial invasion of the tumor, he had pain in the second and third branches of the trigeminal nerve in the left face and paresthesia in the second branch of the trigeminal nerve bilaterally (Numerical Rating Scale: NRS 10/10). Hydromorphone was introduced, and the pain was relieved, but the paresthesia remained (NRS 8/10). Both paresthesia and pain worsened during the course of chemotherapy, but MRI showed no tumor progression, thus, the cause of symptom aggravation was diagnosed edema of the tissue around the tumor. Therefore, Goreisan was started, and both paresthesia and pain were relieved. Discussion: Goreisan has been shown to be effective in cerebral edema due to its water-regulating effect by inhibiting aquaporin. In the present case, the reduction of edema in peritumoral tissues by Goreisan may have contributed to the symptomatic relief.