The integrated management of multimedia in- formation such as images, graphics, video, audio, and text, is of great interest in a lot of application fields. The major challenges in this non-trivial task are due to structural, syntactic and semantic hetero- geneity of distributed multimedia data repositories. In this paper we present the design of a system, IDEM, based on an object-oriented data model and a wrap- per/mediator architecture, which integrates data from heterogeneous multimedia repositories in a single, unified database view, in order to build a multimedia in- formation system capable of integrating data that re- sides in different data base systems as well as in a variety of non-database data servers.