This rapid assessment on the FLAKKA phenomenon in Belgium was created to support the General Drug Policy Cell. The document combines data from all available resources (hospitals, police, court investigations, prevention & harm reduction initiatives, own research, …) ranging from mid-2022 until February 2024. The main questions answered are: 1) what is FLAKKA, 2) which epidemiological data are available and 3) which actions have been or are yet to be undertaken.