The emergence of the Semantic Web has produced several changes in the way in which applications are developed. Besides, the Semantic Web idea has changed itself since its initial appearance. Thus, the most significance change in the most recent proposal of the layer of protocols for the Semantic Web is the use of RDF for data interchange. In this sense, this paper presents a proposal for integrating data sources capable of providing their data as RDF documents. Thus, the use of an ontology-based mediator is able to integrate RDF data taking advantage of a domain ontology.