The study aims to examine the association between exposure to trauma, posttraumatic stress disorder (PTSD), and world assumptions. The study included 3 groups of subjects: PTSD myocardial infarction (MI) patients, non-PTSD MI patients, and matched controls. World assumptions were examined twice: within a week of the patient's MI (Time 1) and 7 months later (Time 2). The findings indicate that world assumptions are not related to exposure to trauma but are associated with PTSD.