It is unknown whether anger is a risk factor for the development of posttraumatic stress disorder (PTSD) symptoms, arises as a consequence of PTSD, or both. Two hypotheses were tested in 180 police recruits: Greater trait anger during training will predict greater PTSD symptoms at one year; greater PTSD symptoms at one year will predict greater state anger at one year. Both hypotheses were confirmed, suggesting that trait anger is a risk factor for PTSD symptoms, but that PTSD symptoms are also associated with an increase of state anger. Increased anger is important not only because of the impact it has on individual distress and physical health, but also because of its potential public health impact.