Poor sleep quality has been linked to posttraumatic stress disorder (PTSD). This study provided a test of how poor sleep quality relates to real-time assessment of anxious reactivity to idiographic traumatic event cues. Script-driven imagery (SDI) was employed to examine reactivity to traumatic event cues among 46 women (mean age = 27.54 years, SD = 13.62; 87% Caucasian) who had experienced either physical or sexual assault. We tested 3 hypotheses: (a) individuals with PTSD would report greater anxiety reactions to SDI than trauma-exposed individuals without PTSD, (b) poorer sleep quality would be positively related to anxiety reactions to SDI, and (c) there would be an interaction between PTSD and sleep quality such that individuals with PTSD and relatively poor sleep quality would report greater anxious reactivity to SDI than would be expected from each main effect alone. Poor sleep quality and PTSD were related to elevated anxious reactivity to trauma cues (sr2 = .06). In addition, sleep quality was negatively associated with anxious reactivity among people without PTSD (sr2 =.05). The current findings, in combination with longitudinal evidence, suggest that poor sleep quality following exposure to a traumatic event may be a risk factor for anxious reactivity to traumatic event cues.