A 6-year-old girl with tuberous sclerosis was found to have multiple intracranial fusiform arterial aneurysms. This represents the fifth reported case of this association. The concepts of an arterial dysplasia being present in cases of tuberous sclerosis and of developmental defects being the cause of some intracranial aneurysms are discussed. The need for a prospective study to assess the prevalence of intracranial aneurysms in patients with tuberous sclerosis is suggested.