SIIRH2020 is the rst edition of the international workshop on Semantic Indexing and Information Retrieval for Health from heterogeneous content types and languages, held as live event on April 14, 2020 in conjunction with the 42nd European Conference on Information Retrieval (ECIR2020). The workshop includes an Open Session covering novel contributions on IR technologies for heterogeneous health-related content open to multiple languages with a particular interest in the exploitation of structured controlled vocabularies and entity linking for document indexing and semantic search applications. We received 7 submissions, and after a careful revision the program committee has selected 3 full papers, 3 short papers. This volume contains all these papers. A MESINESP/Plan TL Session is also part of the workshop for presentation and discussion of current work and new advances in the MESINESP shared task or other medical IR, QA or text categorization evaluation campaigns, as well as the exploitation of evaluation settings and data collections generated through these kind of community evaluation e orts. The Open Session includes two keynote talks, one by Dr. Cher Han Lau, entitled CoronaTracker: A framework for managing and tracking data during crisis, and another by Lucy Lu Wang and Kyle Lo, entitled The COVID-19 Open Research Dataset. The MESINESP/Plan TL Session includes one keynote talk, by Georgios Paliouras, entitled BioASQ: The challenge and the community of biomedical semantic indexing and question answering. We would like to acknowledge all the program committee members, keynote speakers, authors and attendees, and EasyChair for providing such a useful conference management tool for free.