Here is the report of a BioBlitz that took place in Brussels in 2018. “BioBlitz Leopold Park” is a follow-up of how biodiversity has changed –and hopefully increased– in a park located in the heart of Brussels, since the revegetation of the pond and set up of a flowery meadow in 2015. After a short introduction on sampling techniques and insect ecology, 20 citizens were invited to collect insects at the bank of the pond, in the meadow, and in other locations of the park. This participatory event aimed at raising citizens awareness about biodiversity in the city. The material to be used for the observation and identification of the specimens were provided by the Museum staff.