There is growing concern about different criminal manifestations of organised crime, making it necessary to monitor them as serious crime. This is the case of various forms of institutional corruption and socio-economic crime linked to public procurement. The exclusions from public procurement procedures are integrated among the resources available in the legal system to prevent different forms of pressure and influence linked to organised crime, aimed at consolidating positions of political power. The growing relevance of these disqualifications brings to the forefront a unique set of challenges, especially when the decision to exclude economic operators is taken by contracting authorities, as a consequence of a conviction for specific offences. The institutions of the European Union have undertaken an important task of further approximating the different national legislations. This process has been done through a set of Directives known as ‘Fourth Generation Directives’. The transposition of this normative compendium into national legal systems has been carried out in different ways: a) through the incorporation of these exclusions into the legal system of penalties; b) via administrative procedures; c) through combined systems of both criminal and administrative measures. This paper will analyse the different European normative instruments that regulate these exclusions and the transposition of these regulations into different domestic legal systems (mainly, in Spain and Italy). More specifically, it will analyse the opportunities and the significant risks involved in using exclusion mechanisms in public procurement as instruments to counter the infiltration of criminal (particularly, organised criminal) activity into the lawful economy.