Based on a large pool of cross-sectional and longitudinal data, we conclude that workplace bul- lying is a significant predictor for subsequent mental health problems, including depressive-, anxiety-, and PTSD symptoms and other stress-related psychological complaints. By showing that mental health complaints at baseline predict later exposure to workplace bullying we also provide consistent evidence for the bi-directional nature of the association of interest. In order to intervene on the potentially damaging effects of workplace bullying it may be very important to understand the potential vicious circle of workplace bullying and mental health problems [9,12,72]. All in all our findings stress that organizations should prioritize the preventionand management of bullying at work as it has detrimental effects on the mental health of employees.