Objectives. To better understand why some people worry more about terrorism compared with others, we measured how much US residents worried about a terrorist event in their area and examined the association of their fears with their concerns about acute and chronic hazards and other correlates. Methods. In 2008 (n = 600) and 2010 (n = 651), we performed a random-digit dialing national landline telephone survey. We asked about worries about terrorism and 5 other environmental health hazard issues. We also collected demographic and socioeconomic data. Results. Only 15% worried “a great deal” about a terrorist event in their area and 18% to 33% were greatly concerned about other environmental issues. Fear about acute hazard events was a stronger predictor of a great deal of concern about terrorism than were age, race/ethnicity, gender, educational achievement, and other correlates. Conclusions. Those who worried most about acute environmental health hazard events were most likely to worry about terrorism. Also, those who were older, poorer, Blacks, or Latinos, or who lived in populous urban areas felt they were most vulnerable to terrorist attacks. We recommend methods to involve US citizens as part of disaster planning.