A purported pathogenic mechanism for the development of fibromyalgia, a medically unexplained syndrome involving widespread pain, is stress and associated psychiatric disorder. The major stressor of recent World Trade Center terrorist attacks provides a natural experiment for evaluating this mechanism. This study sought to determine whether symptoms consistent with fibromyalgia increased post-September 11 and whether exposure to specific terrorism-related events or prior depression predicted symptom increase. In a large community sample of women in the New York/New Jersey metropolitan area (n=1,312), a cohort initially surveyed for pain and psychiatric symptoms before September 11th were recontacted approximately 6 months after the attacks to assess current symptoms and specific terrorism-related exposures. 'Fibromyalgia-like' (FM-L) four-quadrant pain reports consistent with a diagnosis of fibromyalgia were compared at baseline and follow-up. Result showed that FM-L rates did not increase significantly between baseline and post-attack follow-up. Event exposure did not relate to FM-L onset at follow-up, nor did depressive symptoms at baseline interact with event exposure. Depressive symptoms did not predict new onsets better than the extent of their comorbidity with FM-L at baseline. The failure to detect a significant increase in symptoms consistent with a diagnosis of fibromyalgia and the failure of new onsets of such symptoms to be accounted for by exposure to major stressors or prior depressive symptoms suggests that these hypothesized risk factors are unlikely to be of major importance in the pathogenesis of fibromyalgia.