['A portable practice of repeating a mantram-a sacred word or phrase-has been shown to reduce the severity of posttraumatic stress disorder (PTSD) symptoms in veterans with military trauma. It is thought that the intervention re-directs attention and initiates relaxation to decrease symptom severity, but there may be other mechanisms that may contribute to this improvement.', 'We tested the hypothesis that increases in existential spiritual wellbeing (ESWB) would mediate reductions in self-reported PTSD symptoms following a group mantram intervention.', 'Veterans diagnosed with PTSD from war-related trauma completed 6\xa0weeks of case management plus a group mantram intervention (n\u2009=\u200966) as part of a randomized trial. Measures included PTSD Checklist (PCL) and Functional Assessment of Chronic Illness Therapy-Spiritual Wellbeing. Path analysis was conducted on those who completed treatment to assess ESWB as a possible mediator of change in PCL from baseline to post-treatment.', 'A significant indirect effect, -2.24, 95% CI (-4.17, -1.05) of the mantram intervention on PCL change was found. The path from the mantram intervention to ESWB change was significant and positive (B\u2009=\u20094.89, p\u2009<\u20090.0001), and the path from ESWB change to PCL change was significant and negative (B\u2009=\u2009-0.46, p\u2009=\u20090.001), thus supporting the hypothesis.'] Does spiritual wellbeing mediate PTSD change in veterans with military-related PTSD?