Cavernous malformations (CMs) are a subset of neurovascular malformations, which include arteriovenous malformations (AVMs), venous malformations, and capillary telangiectasias. CMs are referred to by many names, which may contribute to their being mistaken for malignant entities such as angiomas or hemangiomas. They are not, however, neoplastic; they are true vascular malformations with their own natural history and treatment. This article describes CMs and their clinical manifestations, methods of diagnosis, and types of treatment. CMs exist in both sporadic and familial forms. Nurses caring for patients with CMs should be aware of the specific characteristics of CMs that differentiate them from other neurovascular lesions.