The human dimensions of biological invasions have recently become the subject of serious study. Current insight suggests that socioeconomic arrangements can foster or restrict the introduction of new species, and create the conditions for alien species to flourish or fail. Conversely, the human response to species invasions varies, according to the economic and environmental impacts of the invasion and the institutional frameworks of the human groups affected. Using the example of New Zealand, the authors chart changes in public perception of introduced species, and assess the socio-political responses to the ecological and economic consequences of introduced and invasive species. The study also outlines the organisational changes that evolved to combat invasive organisms, and suggests that cultural perceptions and socioeconomic experience of benefits and threats have been the prime determinants of public policy on biosecurity. The authors conclude that biosecurity policies in New Zealand are primarily the outcome of a complex history of European settler aspirations and concerns which attempt to reconcile the country’s economic advantage, as a major agricultural exporter, with a desire to conserve its native flora and fauna as a hallmark of New Zealand’s unique identity and image.