Only a few large families with cerebral cavernous angiomas (CCA) have been reported. We studied 47 members of a four-generation kindred with familial CCA. Thirteen members are affected; of these, eleven (85%) have epilepsy, five (38%) have hearing loss, three (23%) have clinically significant cerebral hemorrhages, one has dementia and progressive pseudobulbar palsy, one has a compressive myelopathy, one has asymptomatic cerebral cavernous angiomas identified by MRI, and another has an adrenal angioma found at autopsy. We developed a phenotypic classification to be used in future gene mapping studies. This classification is based on clinical symptoms, age at onset, concurrent diagnoses, and magnetic resonance imaging (MRI) findings. In the context of this family, this system assigns each member a probability of affectedness that can be used for linkage analysis. We suggest that patients with epilepsy may experience transient poor seizure control due to bleeding from an angioma, and drugs that may induce bleeding from the angiomas, such as valproic acid, should be avoided.