The debate on whether the problem of transnational crime is growing or not rages on. Yet, basic research and reliable data on which to inform this debate are lacking. As a consequence, anecdotal and incomplete information leads to analyses that focus on individual problems and neglect serious structural problems underlying the demand for illegal goods and services. Both theoretical endeavors and ... [Show full abstract] policy construction would thus benefit from some corrective analysis. This paper paves the ground for such analysis by focusing on the interface of legal and illegal actors. It first seeks to clarify the meaning of the terms 'international crime' and 'cross-border crime', often referred to as 'transnational crime'. Secondly, it separates for analytical purposes 'enterprise crime' from 'political crime', while recognizing that the two are often combined in practice. Thirdly, it attempts to construct a typology of legal–illegal links and associations, in order to better organize the existing knowledge and data on this subject. Fourthly, it addresses the question of whether the problem is growing, and if so, why. Finally, it outlines research and policy implications.