This review looks at drivers and enablers of serious organised crime (SOC) in Southeast Asia. The four main forms of SOC in the region are: a) illicit drugs; b) human trafficking and migrant smuggling; c) environmental crimes (e.g. illegal logging, wildlife trade); and d) counterfeit goods. While the situation in each country is different, and there are many country-specific factors involved in SOC in Southeast Asia, the review identified a number of common issues relevant across many countries in the region. For some of these the literature makes a direct correlation with SOC (e.g. expansion of the internet), but for others this correlation is not clearly established: rather, the literature indicates that countries with high levels of SOC have these features. With regard to country-specific information about the causes of SOC, in the time available little was found in the literature on the Philippines and Thailand. However, there was far more on Myanmar, as well as some information on Cambodia and Viet Nam. The remainder of this report looks, firstly, at the main forms of SOC in Southeast Asia and the general factors driving each of these. This is followed by a more in-depth examination of the specific drivers of SOC in Myanmar, Cambodia and Viet Nam.