Over the last dozen years or so there has been a burgeoning of criminal law for purposes of dealing with business cartels in a number of jurisdictions (for instance, the new ‘cartel offence’ introduced under the Enterprise Act 2002 in the UK). The discussion here provides first of all some account of this process of criminalisation, mapping it in terms of jurisdictions and the legal character of this category of cartel offending. It then seeks to explain and account for the phenomenon and more particularly to determine the extent to which it may be seen either as an element of more forceful prosecution strategy, or alternatively as a sea-change in moral perception and evaluation. Put another way, is this a development led by legal policy, or a genuine shift in outlook, which has produced a new legal policy? It will be argued finally that, in a more pragmatic perspective, the success of the criminalisation project in any case depends on the emergence of a genuine sense of ‘hard core’ delinquency, without which effective regulation by means of criminal law is unlikely to be achieved. In this respect, a manufactured sense of moral censure, fostered by prosecutors to facilitate leniency programmes, may (outside the US) eventually prove to be a point of vulnerability in such strategies.