This text constitutes the refereed proceedings of the First International Symposium on Foundations of Information and Knowledge Systems, FoIKS 2000, held in Burg, Germany, in February 2000. The 14 revised full papers and four short papers were carefully reviewed and selected from a total of 45 submissions. Among the topics addressed are: logical foundations and semantics of datamodels; dependency theory; integrity and security; temporal aspects; foundations of information systems design including Web-based information services; and query languages and optimization.