Indexing technique plays a pivot role in the efficient relevant retrieval of multimedia objects. Irrelevant retrieval issue has been encountered in existing indexing techniques because of the complex properties of multimedia objects. Rhetorical Structure Theory (RST) has increased relevant retrieval of text documents by semantically indexing. The focus of research is to propose an indexing technique for multimedia objects using RST concepts. For accommodation of multimedia objects in RST framework; modified version of RST framework has been introduced. Based on modified framework an indexing technique has been proposed. Proposed indexing technique is elaborated by a case study. In analysis phase, comparisons with other existing multimedia indexing techniques are carried out using four metrics: response time, relevancy, index size and precision. Results are compared between proposed and existing multimedia indexing techniques. Proposed indexing technique has given improved results for most of the metrics against compared multimedia indexing techniques.