Cavernous angioma is a benign vascular hamartoma with an obscure etiology. Clinical, radiological, and histological features of 24 cases of cortical and subcortical cavernous angiomas were analyzed to investigate the etiology. The lesions were classified as hemorrhaging (8 cases) or non-hemorrhaging (16 cases) according to the initial symptom. Age, sex, location, calcification and postcontrast enhancement by computed tomography (CT), tumor staining by angiography, and calcification and hemosiderin by histological examination were analyzed. Multivariate analysis showed that calcification by CT and histological examination correlated with non-hemorrhaging cases. Histological examination showed that calcification occurred inside and outside the blood vessels, within the vessel walls and in the adjacent brain tissue. Hemosiderin was also seen in most cases. These findings suggest that cavernous angiomas without hemorrhage have a poor circulation, resulting in minor recurrent bleeding and thrombosis, as well as calcification.