The present study sought to explicate the time-course of posttraumatic stress (PTS)-related attentional bias to threat (ABT) by examining differences in attention bias variability (ABV; a measure which accounts for the temporal dynamics of ABT). A dot-probe task with four presentation durations was used to capture both subliminal and supraliminal stages of processing. Task stimuli consisted of neutral and threat images. Attentional control (AC) was examined as a moderator of the relationship between PTSD and ABV. At an experimental session, participants (PTSD = 11, trauma control = 18) completed questionnaires, a modified dot-probe task, and a stimulus-response task measuring AC. Individuals in the PTSD group exhibited greater ABV compared to trauma control participants. AC moderated this relationship, with participants with PTSD and poor AC exhibiting significantly greater ABV than trauma-exposed control participants with poor AC. These effects remained significant after accounting for traditionally calculated ABT scores and variability on trials for which only neutral stimuli were present, thus ensuring that the observed effects were specific to the presence of threat stimuli and not merely a function of general variability in response times. Findings implicate AC as a buffering mechanism against threat-related attentional dyscontrol among those with PTSD. Clinical implications will be discussed.