Participants' reactions to pretreatment assessments have not been studied as part of a randomized clinical trial (RCT) for posttraumatic stress disorder (PTSD). The current study examined participants' reactions in women with PTSD who completed pretreatment assessments during an RCT. We assessed participant reactions (N = 100) to a pretreatment assessment that included self-report questionnaires, interviews, and psychophysiological assessment. Results indicated that participation in pretreatment assessment was well tolerated as measured by participants' reports of distress, interest level, perceptions of the appropriateness of assessment length, and willingness to participate in a similar assessment in the future. Participating in lengthy pretreatment assessments did not adversely impact treatment participation or outcome.