A Web-based survey of adults who experienced loss during the September 11, 2001, terrorist attacks was conducted to examine the prevalence and correlates of complicated grief (CG) 2.5–3.5 years after the attacks. Forty-three percent of a study group of 704 bereaved adults across the United States screened positive for CG. In multivariate analyses, CG was associated with female gender, loss of a child, death of deceased at the World Trade Center, and live exposure to coverage of the attacks on television. Posttraumatic stress disorder, major depression, anxiety, suicidal ideation, and increase in post-9/11 smoking were common among participants with CG. A majority of the participants with CG reported receiving grief counseling and psychiatric medication after 9/11. Clinical and policy implications are discussed.