Apoptotic cell death has been implicated in the pathogenesis of many human neurodegenerative diseases, including Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral sclerosis. Many currently discussed treatment strategies target the prevention of apoptotic neuron death in the hope of delaying or preventing disease progression. In this article, the morphological and biochemical characteristics of apoptosis are described, and evidence for and against a role for apoptosis in neurodegenerative disease pathogenesis is discussed. Finally, the role of caspase-independent death in neurodegenerative disease pathogenesis is briefly discussed. © 2009 Elsevier Ltd All rights reserved.