Abstract: Research indicates that posttraumatic stress disorder (PTSD) symptoms relate to reckless and self-destructive behaviours (RSDBs). This study examined if positive autobiographical memory (AM) characteristics moderated the relationship between PTSD symptom severity and RSDB engagement among student military veterans. In a sample of 100 trauma-exposed student veterans (Mage = 38.93; 94.6% male), regression analyses revealed that greater PTSD severity was associated with higher engagement in RSDBs (p's < .01), while more accessibility to, greater vividness of, and closer time perspective of positive AMs was associated with less engagement in RSDBs. Moderation analyses revealed that the positive association between PTSD severity and RSDB engagement was stronger at (1) lower (b = 0.21, p < .001) than at higher (b = 0.09, p < .001) levels of positive AM accessibility, and (2) lower (b = 0.21, p < .001) than at higher (b = 0.10, p < .001) levels of positive AM sensory details. Other examined positive AM characteristics - emotional intensity, vividness, and distancing - did not moderate the relationship. Thus, being able to easily remember positive AMs with more sensory details may help attenuate the link between PTSD symptoms and risky behaviours, suggesting that positive memory-based interventions could be helpful. This study was exploratory, and we used a robust yet lenient correction for multiple comparisons, which indicates the need for replication in future research.