This paper analyses the changing nature of organised and serious crime following the peace process in Northern Ireland which officially commenced in 1998. The paper examines those social and situational factors which have led to a rise in crimes perpetrated by both paramilitary Republican and Loyalist organisations, and by the so-called ‘ordinary decent criminals’ (ODCs) unrelated to paramilitary groups. These social and situational factors include political, security and economic variables. As such, Northern Ireland is an important case study of the political context of crime. Whilst the peace process is a positive development, the political transition has had associated unintended effects. The fact that rising crime has resulted from political change should not be taken as an argument against the peace process. Serious crime is defined as indictable offences which by their nature attracts substantial terms of imprisonment. Organised crime is defined in accordance with the National Criminal Intelligence Service as three or more individuals engaging in long-term profit-driven criminal activity (NCIS, 2001). Thus organised crime may include serious offences and other offences (forgery, theft) if they occur as part of organised criminality. The problems surrounding this definition will also be addressed later in the paper.