SummaryEpidemiological studies suggest that the vast majority of people experience at least one potentially traumatic event in their lifetime; however, severe posttraumatic stress symptoms affect only few of those ever exposed to trauma. This study has been aimed to find out whether trait resilience and dispositional optimism are associated with trauma experience and a probable Posttraumatic Stress Disorder (PTSD). A cross-sectional study was conducted, enrolling 300 Lithuanian adults of three different age groups. The Life Events Checklist (LEC), Trauma Screening Questionnaire (TSQ), Resilience Scale (RS-14), and Revised Life Orientation Test (LOT-R) were used to measure potentially traumatic events, posttraumatic reactions, psychological resilience, and dispositional optimism. Results of this study revealed a high prevalence of potentially traumatic events among its participants (95%). Nearly 7% of the total sample had probable PTSD. A significant moderate positive relationship was found between the resilience and optimism, r(300) = .40, p < .01. Optimism was negatively associated with PTSD symptoms, r(214) = –.17, p < .05; however, contrary to what was expected, there was no significant association between the trauma reactions and trait resilience.