Objective: To examine the clinical utility of the Mild Brain Injury Atypical Symptoms (MBIAS) to detect symptom exaggeration in a mixed clinical sample. Method: Participants were 281 patients with mixed etiologies (89.7% male; Age: M = 52.5, SD = 17.0) at a Department of Veterans Affairs neuropsychology clinic. Participants were divided into groups using two different symptom validity test (SVT) criteria: [1] Minnesota Multiphasic Personality Inventory-2 Response Bias Scale (RBS) scores: (a) RBS-Fail (n = 20) and (b) RBS-Pass (n = 105), and [2] Postconcussion Syndrome Questionnaire (PCSQ) total scores: (a) PCSQ-Fail (n = 43) and (b) PCSQ-Pass (n = 225). Results: Participants in the RBS-Fail (d = 1.3) and PCSQ-Fail (d = 1.0) groups had significantly higher MBIAS scores compared to the RBS-Pass and PCSQ-Pass groups (p < .001). Sensitivity, specificity, and predictive power (PP) values were calculated across the range of MBIAS scores. Relative to RBS and PCSQ, the established cutoff of >8 resulted in moderate sensitivity (.58 and .60), specificity (.76 and .79), positive PP (.57 and .61), and negative PP (.77 and .79). An MBIAS cutoff of >11 was considered optimal for differentiating pass/fail groups. This cutoff score resulted in high specificity (.93 and .93); and moderate sensitivity (.40 and .45), positive PP (.76 and .78), and negative PP (.74 and .76). Conclusion: A cutoff of >11 on the MBIAS was found to be most optimal to detect symptom exaggeration. The previously established >8 cutoff resulted in higher sensitivity, but reduced specificity and positive PP. At present, the MBIAS may be used as a “red flag” for further evaluation, but should not be relied on for clinical decision making.