This book presents the first detailed inquiry into the nature of cross-border drug trafficking between Laos People’s Democratic Republic and Vietnam, using an exploratory approach. It draws upon qualitative and quantitative methods, case studies, interviews and survey data from criminal investigation police and drug-related crimes officers (CIPDRC) from six border provinces which are directly and indirectly involved in investigating these cross-border cases. The author demonstrates that drug markets in Vietnam are not controlled by monopolistic, hierarchical organizations or ‘cartels’ but small structures, based on family ties and fellow-countrymen relations, which are fluid and loosely organized. They are very adaptable and sophisticated with diverse modus operandi and multiple divisions of labour which present particular challenges to law enforcement agencies, which the author discusses.