Since the advent of modern neuroimaging (MRI) cerebral cavernomas are usually diagnosed "in vivo". In this paper we describe the data which improved our knowledge of the disease: 1) nosologically, cerebral cavernomas belong to the group of cerebral vascular hamartomas which can be associated between themselves ("mixed" lesions); 2) hemodynamically, the annual risk of hemorrhage increases after a first bleeding and in deep located lesions (brainstem); 3) association between cavernomas and developmental venous anomalies may be observed; the later on must be left in place at operation; 4) immunocytochemical studies (PCNA) show that cavernomas should be considered more as a benign vascular tumor than as a malformation; 5) familial forms (20%) are characterized by multiple locations and "de novo" lesions; 6) better understanding of the natural history of cavernomas, which is a dynamic lesion, leads to broader surgical indications (no alternative treatment).