Objective: Limited research to date has addressed the validity scales of the Behavior Rating Inventory of Executive Function, Adult Version (BRIEF-A), which may be insensitive to symptom over-reporting. This study investigated the relationship among Self-Report BRIEF-A validity scales (Negativity, Infrequency, and Inconsistency) and Minnesota Multiphasic Personality Inventory (MMPI-2) validity scales, followed by an analysis of optimal cut-scores. Method: Correlations among BRIEF-A and MMPI-2 validity scales were calculated in a sample of 115 veterans from a VA medical center. Based on MMPI-2 validity failure, group differences in BRIEF-A Indices were explored, and receiver operating characteristic (ROC) curve analyses were conducted on BRIEF-A Negativity. Results: Only BRIEF-A Negativity significantly correlated with MMPI-2 validity scales, with the strongest correlations with F (rS = .52), FB (rS = .50), and RBS (rS = .46). Individuals with invalid MMPI-2 profiles evinced significantly higher elevations on all BRIEF-A scales, with the exception of Organization (p =.185), compared to individuals who performed credibly (F(9, 81) = 3.70, p = .001, partial η2 = .11 to .22). With specificity at >90%, a cutoff of >3 on BRIEF-A Negativity best discriminated between valid and invalid MMPI-2 profiles, yielding primarily moderate sensitivities (53% to 55%; AUC =.80 to .82) depending on MMPI-2 validity scale used. Conclusion: Of BRIEF-A validity scales, only Negativity was related to MMPI-2 validity scales. Invalidity on the MMPI-2 leads to higher BRIEF-A subscales despite valid BRIEF-A validity scales, suggesting that over-reporting generalizes across tests. A cutoff of >3 Negativity items best discriminated between valid and invalid MMPI-2 profiles. Overall, BRIEF-A validity scales may under-identify response bias.