From 13 to 17 March, the European Centre for Disease Prevention and Control (ECDC) organised the MediPIET Chemical, Biological, Radiological and Nuclear (CBRN) Awareness and Mitigation Module in Petrovac, Montenegro. Fifty participants from more than 20 countries, including 32 Mediterranean and Black Sea Programme for Intervention Epidemiology Training (MediPIET) fellows, attended the five-day training course. The CBRN module was designed to explain the principles and processes for preparedness and response to threats to human health caused by chemical, biological, radiological, and nuclear agents.