Objective: This mixed-methods study assessed the prevalence of pre-and postmigration trauma and stressors as determinants of refugee mental health in resettlement. Method: Forty-four war-affected Syrian civilians arriving in Portugal through four streams-UNHCR resettlement, EU relocation, spontaneous asylum, and higher education programs for refugees-participated in focus groups and individual interviews. Participants completed self-report measures of trauma and torture and PTSD symptoms, and narrated pre- and postmigration experiences and distress through semistructured interviews. We used descriptive statistics to characterize incidence of trauma and distress, and thematic analysis to identify themes of pre- and postflight stressors. Results: Participants reported a mean 12.9 (SD = 7.2) war trauma events, with six men also disclosing having been tortured. Twenty-five percent met diagnostic criteria for PTSD. Key results identified preflight contextual, personal, family, and community daily stressors capable of shattering prewar meaning systems, and postflight common stressors aggravated by state-sponsored host conditions, the ongoing conflict, and, for the student group, subsequent to temporary returns to Syria. Conclusion: Regardless of legal status on arrival, civilians from war-torn countries may be exposed to pre- and postmigration trauma and stressors that severely impact their mental health, reinforce feelings of uprootedness, and dim integration prospects. Findings highlight the need for host countries to create opportunities for agency and autonomy to improve refugees' own integration prospects and ability to initiate their path to recovery. (PsycInfo Database Record (c) 2022 APA, all rights reserved).