This study examined the Trauma Symptom Inventory (TSI; Briere, 1995) in a sample of 62 trauma-exposed community residents (80% Caucasian, 89% women), including 16 who had posttraumatic stress disorder (PTSD). PTSD and non-PTSD groups differed on seven TSI clinical scales and one validity scale, with effect sizes (r) ranging from 0.26 to 0.53. The largest effect sizes and best diagnostic utility were found for the Defensive Avoidance and Anxious Arousal scales. Diagnostic utility analyses suggest that TSI subscales in isolation are not superior to existing measures of PTSD. A logistic regression using the five most discriminating TSI scales produced a correct classification rate of 85.5%. TSI scales also demonstrated good convergent validity with other measures of PTSD. Overall, the results provide preliminary support for the use of the TSI in the assessment of PTSD.