Abstract: Objective: Prolonged exposure (PE) is an effective treatment for posttraumatic stress disorder (PTSD), but veterans with sexual assault (SA) trauma often discontinue it prematurely. Elevated dropout rates may be due to SA triggering more intense and complex emotions that are more difficult to habituate during imaginal exposures; SA during PE has yet to be examined as a moderator of distress habituation or symptom reduction. Method: Participants were N = 65 veterans (n = 12 SA treatment focus; n = 10 SA history but not treatment focus; n = 43 no SA history) enrolled in a clinical trial of a preparatory sleep intervention followed by PE. The sample was representative of the veteran population. Growth curve modeling was used to examine differences in peak subjective units of distress scale (SUDS) ratings across imaginal exposures and changes in biweekly PTSD symptom assessments between veterans who did versus did not focus on SA during PE and between veterans who did versus did not endorse a history of SA. Results: Peak SUDS ratings and PTSD symptoms declined slower among veterans who focused on an SA trauma relative to those who did not. In contrast, participants who endorsed SA history showed similar declines in distress and PTSD symptoms relative to veterans with no SA history. Conclusions: Veterans who focus on SA during PE may take longer to habituate to trauma content and experience resolution of PTSD symptoms. Awareness of this pattern could allow clinicians to deliver PE more effectively to veterans focusing on an SA trauma.