This book constitutes the refereed post-conference proceedings of the 9th International Conference on Mobile Communication and Healthcare, MobiHealth 2020, held in December 2020. Due to Covid-19 pandemic the conference was held virtually. The book contains 13 full papers selected from the main conference and 10 full papers from two workshops on medical artificial intelligence and on digital healthcare technologies. The conference papers are organized in topical sections on wearable technologies; health telemetry; mobile sensing and assessment; machine learning in eHealth applications.