Apoptosis (Programmed Cell Death) is coordinated by a family of cysteine proteases-the caspases-that dismantle the cell by cleaving a subset of cellular proteins after aspartic acid residues. Caspases participate in the molecular control of apoptosis in several guises; as triggers of the death machinery, as regulatory elements within it, and ultimately as a subset of the effector elements of the machinery itself. The mammalian caspase family is steadily growing and currently contains 14 members. At present, it is unclear whether all of these proteases participate in apoptosis. Our current research in this area is focused upon establishing the repertoire and order of caspase activation events that occur during the signalling and demolition phases of cell death. Evidence is accumulating to suggest that apical caspase activation events are initiated by molecules that promote caspase aggregation and facilitate autoactivation. Distal caspase activation events are controlled by caspases activated earlier in the cascade. Recent research indicates that numerous pro-apoptotic stimuli converge on mitochondria and provoke the release of factors (such as cytochrome c) that trigger caspase activation and cell death as a consequence. Here, we discuss the apoptosis-associated caspase cascade that is triggered upon release of mitochondrial cytochrome c into the cytoplasm and the hierarchy of caspase activation events within this cascade.