Purpose -This study aims to understand key features of existing multilingual digital libraries and to suggest strategies for building and/or sustaining multilingual information access for digital libraries. Design/methodology/approach -A case study approach was applied to examine four American multilingual digital libraries: Project Gutenberg, Meeting of Frontiers, The International Children's Digital Library, and the Latin American Open Archives Portal. This examination used a framework derived from digital library evaluation practice. The missions, goals, funding, partners, users, collections, services, and technologies of these digital libraries were analyzed to present their key multilingual features . The collaboration and crowdsourcing characteristics were highlighted and discussed. Findings -These four multilingual libraries benefit substantially, both in the creation of the library and in its access, from the collaboration of groups domestic and international with different language expertise. For building the multilingual collection and services, some libraries involved both staff and users. For multilingual access to the collection, however, none of the libraries used machine translation or crosslanguage information retrieval technologies. Research limitations/implications -The four cases are all publicly available digital libraries in the United States. Their features may not be applicable to digital libraries in other countries or to commercial digital information services. Practical Implications -With the advancement of machine translation technologies and the wide application of social media, multilingual digital libraries may have even better opportunities to sustain their multilingual capabilities through crowdsourcing and the application of new technologies. Originality/value -This study summarizes the key features of four existing multilingual digital libraries. It provides insights into important factors for building successful multilingual digital libraries. The suggested strategies may help digital library developers to design appropriate multilingual information access services.