The basic elements of the machinery of programmed cell death (apoptosis) are built into all mammalian cells and are conserved evolutionarily from nematodes to humans. The workshop on Commitment to Radiation-Induced Apoptosis at the 11th International Congress of Radiation Research in Dublin, Ireland reviewed recent information regarding the basic molecular mechanisms which are fundamental to the understanding of the process of apoptosis after treatment with ionizing radiation and some other agents.