Little information exists on the contribution of psychological strengths to well-being in persons with post-traumatic stress disorder (PTSD). Data from other populations suggest that gratitude, defined as the positive experience of thankfulness for being the recipient of personal benefits, may have salutary effects on everyday functioning. We investigated whether dispositional gratitude predicted daily hedonic and eudaimonic well-being in combat veterans with and without PTSD. We also examined associations between daily gratitude and daily well-being across time. Veterans with PTSD, compared to those without PTSD, exhibited significantly lower dispositional gratitude; no differences were found on daily gratitude. Dispositional gratitude predicted greater daily positive affect, percentage of pleasant days over the assessment period, daily intrinsically motivating activity, and daily self-esteem over and above effects attributable to PTSD severity and dispositional negative and positive affect in the PTSD group but not the non-PTSD group. Daily gratitude was uniquely associated with each dimension of daily well-being in both groups. Although preliminary, these results provide support for the further investigation of gratitude in trauma survivors.