We studied the etiology of seizures in 46 patients who developed seizures after age 65 years. The most frequent cause was cerebrovascular disease, accounting for 41.3% of all cases. Clinical diagnosis of Alzheimer's disease was made in 5 patients (10.8%). Other etiologies were; metabolic encephalopathies in 6.5%, craniocerebral trauma in 4.3% and glioma in 2.1%. The etiology of seizures remained unknown in 34.7%. They had generalized tonic-clonic seizures in 48%. They were partial or partial secondarily generalized in 44.1%. The role of Alzheimer's disease in late onset seizures has not been important enough in previous studies. We believe that a well-designed prospective study will let us know the real frequency of the causes of seizures in the elderly.