Apoptosis is a form of programmed cell death important in the development and tissue homeostasis of multicellular organisms. Abnormalities in cell death control can lead to a variety of diseases, including cancer and degenerative disorders. Hence, the process of apoptosis is tightly regulated through multiple independent signalling pathways that are initiated either from triggering events within the cell or at the cell surface. In recent years, mitochondria have emerged as the central components of such apoptotic signalling pathways and are now known to control apoptosis through the release of apoptogenic proteins. In this review we aim to give an overview of the role of the mitochondria during apoptosis and the molecular mechanisms involved. (C) 2002 Societe francaise de biochimie et biologic moleculaire / Editions scientifiques et medicales Elsevier SAS. All rights reserved.