A 41-year-old woman presented with disturbance of consciousness, right hemiparesis, and symptoms of Gerstmann syndrome. She had a history of malignant melanoma resections of an ear mole and her right neck lymph nodes and parotid gland, with subsequent chemotherapy and radiotherapy. Computed tomography showed two large lesions in the right frontal and left parietal lobes surrounded by severe brain edema. Magnetic resonance images revealed that the two lesions were strongly enhanced with cystic change, and a small round lesion was located in the left head of the caudate nucleus. (18F) fluoro-2-deoxyglucose positron emission tomography showed high accumulation in both lesions, and no sign of metastatic lesions except within the brain. The two lesions were large, causing increased intracranial pressure. Simultaneous surgical resections were performed using two approaches. The patient's neurological symptoms were greatly improved after surgery, and her Karnofsky Performance Status improved from 20% to 90%. She was discharged to her home almost completely free of neurological deficits. Although, simultaneous one-stage tumor resections for multiple metastatic brain tumors do not extend the survival period, they improve the quality of the patient's limited remaining life, and may be a treatment choice for young patients with well-controlled systemic disease.