This study examined workplace aggression among a Dutch group of 174 prison workers at 10 penitentiaries in the Netherlands. The purpose of the study was to investigate the main and interaction effects of Type D personality and violence on posttraumatic stress disorder (PTSD). The results showed a significant interaction effect between the type of violence and Type D personality. Physically violated Type D individuals achieved the highest average score on the PTSD scale. Type D personality was found to have a strong main effect on PTSD.