Pedro Ferreira was on Wurzburg, Germany, as a co-organizer of the the first edition of the Workshop on Machine Learning for CyberSecurity – MLCS 2019, co-located with ECMLPKDD 2019. Ibéria Medeiros was also on MLCS 2019 organizing committee. The workshop had 18 paper submissions and 5 accepted papers. Mario Fritz, from CISPA Helmholtz Center for Information Security, gave an invited talk: Towards Trustworthy AI. Finally, an open discussion panel was organized on the Future directions of research in machine learning for cybersecurity.