The conference "NaNaX 9 - Nanoscience with Nanocrystals" was held from 16.9. - 20.9.2019 at Universität Hamburg, organized by the physics and chemistry departments. NaNaX is a conference series established in 2003 and has since then developed to a leading conference series in Europe about chemically and physically manufactured nanostructures, their characterization, and application. Wolfgang Parak, who joined the Universität Hamburg in 2017 is one of the co-founders of NaNaX. Together with Neus Feliu, Alf Mews, and Horst Weller and their groups NaNaX 9 was organized in Hamburg located at Fachbereich Chemie. The conference was held in an open atmosphere, allowing for a lot of discussions between participants, which was fostered by poster sessions with buffet, and a home-prepared paella by the organizers for all 200 participants