Background: Extremely violent events such as terrorist attacks and mass shootings form a severe risk for the health and wellbeing of affected individuals. In this study based on a public health monitor, we focus on the health impact (including PTSD symptoms, physical problems and day-to-day functioning) of the Utrecht tram shooting, which took place in the morning of March 18th 2019. A lone gunman opened fire on passengers within a moving tram. Four people died, and six people were injured in this attack.