Objective: Instructions for the MENT specifically mention that PTSD can affect performance. There are ethical implications for utilizing deception and capitalizing on suggestibility in assessment. We explore the effect of using deceptive language in instructional sets when assessing PTSD symptom exaggeration. Method: Participants (N = 101) referred for neuropsychological evaluation at a VA medical center were either service-connected for, had previously been diagnosed with, or self-identified as having PTSD or PTSD symptomatology. Participants were predominately male (n = 95) and averaged 12.8 years of education (SD = 2.1), with an average age of 46.1 years (SD = 15.0). One group received standard instructions (SI; n = 68) and another group received revised instructions (RI; n = 33), removing reference to PTSD. Results: Groups did not differ across age or education (p > .05), and there were no group differences in Posttraumatic Stress Checklist scores (p > .05; overall M = 59.7, SD = 16.1) or Word Memory Test failure rate (p > .05). However, MENT scores differed significantly based on instructional set, F(1, 99) = 5.6, p = .02, with RI resulting in fewer errors. The SI group was more likely to meet MENT failure criteria, χ2 = 7.5, p < .01. Conclusion(s): When the MENT instructional set was altered to remove reference to PTSD, error scores and failure rates significantly decreased, suggesting that deceptive language is seemingly necessary for eliciting PTSD symptom exaggeration with the MENT. Clinical and ethical implications are discussed.