Sustainability issues and matters involving the conservation of biodiversity are no longer new subjects for environmental policy. Nevertheless, they are of continuing interest, there are always new dimensions to consider and unresolved questions remain. In fact, it may only be now that we are starting to have a satisfactory overview of these subjects which have been intensively considered for around two decades. This paper provides an overview of this subject, paying particular attention to agriculture. In it the following are considered: 1. Different broad approaches to policy-making and implementation applied to environmental policies. 2. Different concepts of and views about sustainability- and biodiversity and their dissimilar policy implications. 3. Agricultural sustainability as a concept and as a goal, and policies to achieve agricultural sustainability. 4. Important relationships between agriculture and the conservation of biodiversity. 5. Reasons for sustaining biodiversity, possible methods for doing so, and their implications for agriculture.