The ?rst International Symposium on the Applications of Constraint Databases (CDB2004) took place in Paris, France, on June 12-13, 2004, just before the ACM SIGMOD and PODS conferences. Since the publication of the paper "Constraint Query Languages" by Kan- lakis, Kuper and Revesz in 1990, the last decade has seen a growing interest in constraint database theory, query evaluation, and applications, re?ected in a variety of conferences, journals, and books. Constraint databases have proven to be extremely ?exible and adoptable in environments that relational database systems cannot serve well,...