This article draws attention to the relevance of criminological insight on issues of international criminal law and criminal justice. In particular, the ideology and theory of deterrence, legitimacy, and international criminal law are drawn from. After all, the deterrent effect has been touted as a solid empirical fact with the progression and development of 'international criminal justice', the international tribunals since the mid 1990s, and the International Criminal Court. Yet, the current rather blind belief in the deterrent impact of international criminal justice remains, regretfully, a bit premature. Additionally, beyond the concepts of deterrence and legitimacy, criminologists have much to contribute to international criminal justice. As noted, there are social, political, cultural, and geographical issues that play a role in not only crime commission, but in the hindrance of and/or facilitation of deterrence. Criminologists are well positioned to show how these connections may facilitate or hinder the broader goals of the legal community.