The current study examined anniversary reactions in mental health disaster relief workers following traumatic exposure at the site of the World Trade Center terrorist attacks. Despite relatively low levels of symptom reporting, workers endorsed an increase in both negative mood symptoms and functional impairment at the one-year anniversary of their traumatic exposure (compared to 6 months postexposure). For those individuals who met at least partial criteria for PTSD immediately following exposure, overall self-reported PTSD symptoms tended to increase from 6 to 12 months. This tendency resulted specifically from an increase in hyperarousal symptoms. Although few endorsed symptoms at clinical levels, our results demonstrate that disaster relief workers may experience an increase in symptomatology at the anniversary of their traumatic exposure.