Rates of posttraumatic stress are elevated in individuals who have experienced childhood and/or cumulative trauma, and trauma appraisals have been suggested as a possible mediator of this effect. This study tested the proposed mediating role of trauma appraisals between both childhood and cumulative trauma, and two markers of trauma-related distress; posttraumatic stress and depression. Mediation models were developed and tested with data collected from a sample of trauma-exposed, treatment receiving adults (N = 106). Trauma appraisals fully mediated relationships between childhood trauma and PTSD/depression. Appraisals also mediated the relationships between cumulative trauma and depression. When appraisal subscales were simultaneously entered, alienation appraisals were the only significant mediator of these relationships. The study found support for the proposed mediating role of trauma appraisals between different forms of trauma and trauma related distress. Alienation appraisals were particularly emphasised.