It is now generally accepted that massive neuronal death due to oxidative stress is a common characteristic of brains in neurodegenerative disease. Recently, numerous apoptosis-regulating factors and multiple pathways have been identified, and apoptotic cell death has been implicated in neuronal loss in Alzheimer's disease. Although glial cells are more resistant to oxidative stress than neurons, extensive oxidative stress seems to cause apoptotic cell death in glial cells. In fact, signs of apoptosis are observed in both neurons and glial cells in the brains of patients with Alzheimer's disease. This review summarizes current findings regarding apoptotic processes and discusses the possible involvement of apoptosis-regulating factors in the pathology of Alzheimer's disease.