This study examines the association of life stressors and the period when they occur, with the development of chronic fatigue syndrome (CFS) symptoms in Gulf War veterans. Of data collected from Gulf War Health Registry veterans, 113 met CFS criteria and 441were controls. After hierarchical multiple regression, several negative life stressors were associated with CFS group membership: being wounded, experiencing a traumatic war experience, frequent battle experiences, demotion, and unable to work within 2 years of returning from the Gulf.