Primary high-grade lymphoma of the dura mater and cranial vault has rarely been reported. The authors treated a 61-year-old man who presented with a slow-growing scalp mass that involved the cranial vertex. Magnetic resonance imaging revealed an oval mass of the dural type with peripheral edema in the bilateral parietal region, with attachment to the cranial vault and extension to the subgaleal space. After subtotal resection, pathological examination yielded a diagnosis of malignant large B-cell lymphoma. Twenty-three months postoperatively, after undergoing radiation therapy and chemotherapy, the patient is neurologically intact and without systemic dissemination of the malignancy. This is a case of primary malignant B-cell lymphoma of the dura mater with extensive involvement of the skull, which is a very rare event. Imaging-based diagnosis and combined therapy consisting of surgery, radiation therapy, and chemotherapy for the disease are discussed, and the literature on extraaxial malignant lymphomas is extensively reviewed.