In the late 1980s the demands for a more ecological life style and sustainability set off intense research for methods to analyse and assess the environmental impact of products and systems. The methodology crystallizing from this research is called life cycle assessment (LCA). This paper presents the concept, methodology, applications and present status of LCA. LCA as applied to food production systems is discussed in terms of needs, special demands on methodology, the studies that have been performed and ongoing activities. © 1994.