Post-traumatic stress disorder (PTSD) diagnosis often depends on a retrospective, self-report of exposure to a life-threatening event.

To examine the stability of recalled perceived life threat in a community sample exposed to a distinct stressful event.

Five hundred and thirty-two Norwegian citizens who experienced the 2004 South-East Asia tsunami completed a self-report questionnaire 6 and 24 months post-disaster. The questionnaire measured perceived life-threat intensity, exposure, immediate stress response, psychopathology, personality dimensions, self-efficacy and social support.

Recalled threat intensity increased from 6 to 24 months (P <0.001). Recall amplification was associated with lack of PTSD symptom improvement (P < 0.05), but not with degree of exposure, immediate stress response, mood or stress symptoms, personality, self-efficacy or social support.

Recall amplification of perceived life threat from a single stressful event occurs in the general population, it may hinder PTSD symptom improvement and it questions the diagnostic validity of PTSD.