The Symptoms of Trauma Scale (SOTS) is a 12-item, interview-based, clinician-rated measure that assesses the severity of a range of trauma-related symptoms. This pilot study evaluated its use and psychometric properties in an outpatient setting that provides treatment to survivors of chronic interpersonal trauma. Thirty participants completed self-report measures of posttraumatic stress symptoms, depression, dissociation, self-esteem, and affect dysregulation; the participants also participated separately in a semistructured interview based on the SOTS conducted by 2 trained interviewers. SOTS composite severity scores for DSM-IV posttraumatic stress disorder (PTSD) and complex PTSD (cPTSD), DSM-5 PTSD, and PTSD dissociative subtype, and total traumatic stress symptoms generally had acceptable internal consistency and interrater reliability. Evidence of convergent, discriminant, criterion, and construct validity was found for the SOTS composite PTSD scores, although potential limitations to validity that require further research and refinement of the measure were identified for the SOTS total and DSM-IV cPTSD scores and the hyperarousal, affect dysregulation, and dissociation items. Interviewers and interviewees described the interview as efficient, informative, and well tolerated. Implications for clinical practice and research to refine the SOTS are discussed.