The chapter goal is to provide responses to the following question: how the ontologies could be used in order to index and manage the multimedia collections? Alongside with reviewing the main standard formats, vo-cabularies and ontology categories developed especially for multimedia content description, the chapter em-phasis the existing techniques for acquiring ontology-based indexing. Since a fully automatic such technique is not possible yet, the chapter also proposes a solution for indexing a multimedia collection by combining technologies from both semantic Web and multimedia indexation domains. The solution considers the man-agement of multimedia metadata based on two correlated dictionaries: a metadata dictionary centralizes the multimedia metadata obtained through an automatic indexation process, while the visual concepts dictionary identifies the list of visual objects contained in multimedia documents and considered in the ontology-based annotation process. This approach facilitates as well the multimedia retrieval process.