Sheep production may impact locally on water, air and soil quality, as well as globally, for example contributing to greenhouse gas emissions. Sheep production can also impact biodiversity, human health via various pollutants, and community and cultural well-being. This chapter examines how life cycle assessment (LCA) can be used as a tool to quantify multiple resource use and environmental impacts. A detailed comparative case study of sheep production in France and New Zealand using LCA examines how potentially harmful emissions can be assessed and measured at each stage in the life cycle of sheep products, so that the most damaging stages can be identified and steps can be taken to mitigate them. The chapter offers indications of future trends in research in this area.