PRIMARY OBJECTIVE: The Depression Anxiety Stress Scales (DASS) and its shorter version, the DASS21, demonstrate a consistent factor structure. However, when these scales are used with people with traumatic brain injury (TBI), it is possible that TBI symptoms that overlap with anxiety and depression (e.g., irritability, inertia, emotional lability) result in changes to the underlying structure. This study aimed to establish whether the factor structure of the DASS and DASS21 when used with individuals with TBI is consistent with the three scales designated in the manual. METHODS AND PROCEDURES: One hundred and twenty-three participants with mild-to-severe TBI completed the DASS. MAIN OUTCOMES AND RESULTS: The factor structure of the DASS was found to be consistent with the designated scales, with the exception of four items that cross-loaded weakly on multiple factors. However, the factor structure of the DASS21 did not correspond as closely to the designated depression, anxiety and stress scales, which appeared to be due to the fact that many of the highest loading items on the DASS were not included items in the DASS21. CONCLUSIONS: These results indicate that it may be preferable to use the full DASS, rather than the DASS21, with individuals with TBI.