This thesis provides a critique of the penology of capital punishment from the perspectives of Christianity and Islam. In order to ascertain the basic theological approaches of both religions towards capital punishment, Chapters 2 and 3 examine the core Scriptural texts, laws and traditions of both Christianity and Islam respectively. These chapters reveal how different methods of Scriptural interpretation and differences in religious practice, within each faith, have led to divergent opinions regarding the legitimacy and acceptability of capital punishment. Chapters 4 and 5 examine two of the primary penological justifications for the death penalty; retributivism and deterrence. It is demonstrated how they can be used, within secular and religious frameworks, to both condemn and condone the use of the punishment. Chapter 6 considers a variety of contemporary methods used to execute offenders and asks whether the methods used have any effect on the religious acceptance or rejection of the penalty. Finally, Chapter 7 presents one of the most controversial aspects of the contemporary death penalty debate, namely the unequal application of the penalty as it pertains particularly to black offenders, indigent offenders and mentally ill offenders. This serious criticism of the death penalty is considered first in general secular terms and then in light of the teachings of both religions and it is asked how the religious arguments in favour of the death penalty stand in light of such serious violations of human rights and justice. The thesis concludes with the assertion that, while a strong case can be made from within both religions for the use of capital punishment in principle, in practice given current practices of criminal justice systems worldwide there is a strong case to be made, if not for abolition, then at least for a drastic curtailment of the practice and a long-term moratorium on capital punishment on religious grounds.