An indirect/nonreactive technique of assessing spontaneous concern should be used to examine the salience of the threat of nuclear war. Direct/reactive techniques may produce inconsistent results and inadvertently enhance a false consensus. The procedures for the administration, scoring, and interpretation of a spontaneous concern measure along with acceptable reliability and validity estimates are reported. The salience of the threat of nuclear war is associated with worrying about nuclear war more often, higher levels of other nuclear worries, anxiety, depression, anger, and a greater fear of the future in general. Nuclear threat salience does not appear to be associated with several indicators of general anxiety or mental health, but it is moderately associated with the placing of a higher priority on the value of a world at peace. The document includes a list of twenty-three references, two tables of statistics, and two tables of sample questions and scoring guidelines. (Author/PPB)