The relationships of economists with ecologists and conservationists have improved following global interest in the concept of sustainable development. In addition, international and other bodies interested in nature conservation have increasingly turned to economics to provide justifications for nature conservation projects and policies to support these. While this is welcome, it behoves users of such techniques to be aware of their limitations, as well as their advantages. As a first step, it is useful to be aware of the ethical foundations of economic analysis. These are outlined. As a prelude to discussion of the use of social cost-benefit analysis as a method of evaluating nature conservation, classifications of the economic values of wildlife are- discussed. Classificatory schemes are a useful aid to determining the total economic value of wildlife and it is emphasised that both consumptive values and non-consumptive values are important. While social cost-benefit analysis is a well-developed technique for economic assessment and has been widely applied to nature conservation projects, it is not without critics. Critics include those who support the use of safe minimum standards. For nature conservation this is often taken to imply a minimum viable population of a species and requisite habitat to support it. Further qualifications to the use of social cost benefit analysis have been made by advocates of strong conditions for sustainability and the implications of these for nature conservation are considered. Economic reasons for biodiversity conservation are outlined but it is concluded that economists still have a long way to go in determining economic values for biodiversity. Selected economic policy proposals and issues are discussed. Limits to private property (privatisation) as a means for nature conservation are mentioned and risks associated with the commercialisation and farming of species from the point of view of biodiversity loss are discussed. The problem of biodiversity loss in less developed countries is given particular attention. In conclusion, it is stated that connections between economic analysis and nature conservation can be expected to grow. Even in cases where values are not entirely anthropocentric, economics will have a policy role because cost effectiveness is likely still to be relevant.