This paper describes the COVID-19 DataSharing/BR initiative, a pioneer public-private partnership to publish open data on Brazilian COVID-19 patients. Constructed in record time, it has been launched with clinical, laboratory and diagnostic data from approximately 177,000 Brazilian individuals, in answer to researchers’ demand for quality data. COVID-19 DataSharing/BR was created by a consortium led by FAPESP (Sao Paulo Research Foundation) and USP (University of Sao Paulo, Brazil), with participation from three major private health institutions in Brazil – Fleury Institute, Sírio-Libanês Hospital and Albert Einstein Hospital. Launched on July 1st, 2020, within 10 days it had already been subject to 800 downloads from 14 different countries.This text provides a brief description of the initiative, and initial efforts for preprocessing and publishing the data according to legal and interoperability constraints. The COVID-19 DataSharing/BR repository took only one month from inception to delivery, thanks to the support of a pre-existing extensible open research data e-infrastructure.