Attentional threat bias (ATB) has been suggested as one factor leading to maintenance and exacerbation of posttraumatic stress symptoms (PTSS). In the present study, attentional processes (i.e., facilitated engagement, difficulty disengaging) underlying the association between ATB and PTSS were examined. Additionally, attentional control (AC) was examined as a moderator of this relationship. Participants (N=97) completed a dot-probe task with two levels of stimulus-onset asynchrony (SOA: 150 and 500ms). Higher PTSS were associated with ATB when SOA was longer (i.e., 500ms), suggesting difficulty disengaging from threat stimuli. AC moderated the relationship between PTSS and ATB when SOA was shorter (i.e., 150ms), with participants high in PTSS and high in AC having disengaged and shifted attention from threat stimuli using top-down AC when the emotional valence of threat stimuli was less salient (i.e., shorter presentation duration). Findings implicate AC as a buffering mechanism against prolonged attentional engagement with threat-related stimuli among those with high PTSS. Current PTSD interventions may benefit from incorporating attention-based components.