Integration of the World Wide Web and other information sources is strongly required in the recent advanced application en-vironments. Although information sources contain various types of data objects, the volume of multimedia objects has been increasing drastically. This paper proposes a multimedia integration scheme using SMIL in a mediator-based integration system. The scheme achieves dynamic creation of various Web views combining multimedia objects stored in heterogeneous information sources such as the Web, structured documents, and databases. A key point is to utilize SMIL as a framework for dynamic multimedia integration. Since there already exist some players for SMIL documents, dynamic integration results including multimedia objects can be rendered in such players, without special-purpose ones, and are ready to be broadly distributed. The main contributions of the paper are the followings. (1) We propose a dynamic, SMIL-based multimedia integration scheme. This scheme utilizes an extended relational data model named WebNR/SD. (2) We report on imple-mentation of the proposed scheme. We have already implemented the first prototype system which realizes integration of heterogeneous information sources including multimedia objects. Actually, it can construct SMIL-based multimedia views dynamically. This shows the practical significance of our scheme.