The primary motivation behind this thesis was to examine how illicit drugs represent a multidimensional threat to the security of Pacific island states and the region as a whole. However, this research was presented with significant challenges before it began, which included the illegality of the subject matter, the confidentiality of law enforcement intelligence and the fact that there was a near total absence of academic research and statistics concerning drugs within the region. In order to overcome these challenges, this thesis blends a synthesis of conflict and security literature, reports from international and non-governmental organisations and the concepts of securitisation developed by Barry Buzan, Ole Waever & Jaap de Wilde in Security: A Framework for Analysis (1998). The domestic environment of the states that form the case studies are examined, the negative influences of drugs are presented and the perceptions and responses of the governments are discussed. Furthermore, the comparative aspect of this thesis, where two case studies are drawn from the Caribbean, Jamaica and Haiti, and two from the Pacific, Papua New Guinea and Fiji, ensures a thorough understanding of the complex challenges posed to state security, and provides a window for examining how states with similar characteristic and weaknesses are threatened by drugs. For example, throughout Papua New Guinea, marijuana has facilitated the acquisition of small arms and light weapons by both criminal groups and villages involved in conflict. In Fiji, there is the potential for the trafficking of drugs to destabilise the state by providing support to criminal groups and those currently involved with transnational criminal activities. This thesis concludes that the cultivation, production and trafficking of illicit drugs present an immediate and long-term threat to the Pacific, and that the security architecture for the region must be enhance to combat this formidable threat.