Bookmarks are shortcuts that enable quick access of the desired Web content. They have become a standard feature in any browser and recent studies have shown that they can be very useful for non-visual Web access as well. Current bookmarking techniques in assistive Web browsers are rigidly tied to the structure of Web pages. Consequently they are susceptible to even slight changes in the structure of Web pages. In this paper we propose semantic bookmarking for non-visual Web access. With the help of an ontology that represents concepts in a domain, content in Web pages can be semantically associated with bookmarks. As long as these associations can be identified, semantic bookmarks are resilient in the face of structural changes to the Web page. The use of ontologies allows semantic bookmarks to span multiple Web sites covered by a common domain. This contributes to the ease of information retrieval and bookmark maintenance. In this paper we describe highly automated techniques for creating and retrieving semantic bookmarks. These techniques have been incorporated into an assistive Web browser. Preliminary experimental evidence suggests the effectiveness of semantic bookmarks for non-visual Web access.