Objective: The authors examined the ability of college students to simulate ADHD symptoms on objective and self-report measures and the relationship between knowledge of ADHD and ability to simulate ADHD. Method: Undergraduate students were assigned to a control or a simulated ADHD malingering condition and compared with a clinical AD/HD group. The authors used several clinical attentional measures and symptom validity tests to differentiate experimental groups via a series of multivariate procedures. Results: Simulators successfully feigned ADHD symptoms on a retrospective self-report measure. Moreover, knowledge of ADHD was unrelated to objective attentional measure performance. Overall, participants who simulated ADHD on some objective measures (i.e., specific Wechsler Adult Intelligence Scale-III [WAIS-III] subtests) showed similar performance to the clinical ADHD comparison sample. Conclusion: The implications of these findings highlight the importance of relying on multiple vectors of information, be it objective, observational, self-report, or reports by others, when diagnosing ADHD and assessing factors related to potential secondary gain. (Contains 4 tables.)