Objective: There is growing emphasis on assessment of functional impairment for both diagnosing psychological disorders and for making judgments about disability and/or accommodations. Unfortunately, the focus to date has been on self-reported functional impairment, which, like self-reported symptoms, is likely vulnerable to malingering. In the present study, we examined whether a highly recommended self-report measure of functional status (World Health Organization Disability Assessment Scale; WHODAS) is vulnerable to malingered Attention Deficit Hyperactivity Disorder (ADHD). Method: Using a simulator design, undergraduate students were randomly assigned to 1) malinger ADHD for the purposes of receiving stimulant medication, 2) malinger ADHD for the purposes of receiving extended time accommodations, or 3) give their best effort. They were given a large battery of self-report and neuropsychological tests, including the WHODAS, which was the focus of the present analyses. Results: The three groups were significantly different on the Understanding and Communicating, Life Activities – Household, and Participation in Society subscales of the WHODAS. Bonferroni-corrected follow-up testing showed that both malingering groups reported significantly more impairment in Life Activities than controls, while individuals malingering for medications reported significantly more Understanding and Communicating impairment than controls, and individuals malingering for extended accommodations reported significantly more impairment in Participation in Society than controls (all p < .05). Conclusion: Results provide preliminary evidence that malingering can affect self-reported functional impairment, and future studies should continue to examine how best to assess functional impairment, as well as consider ways in which one can determine the accuracy of self-reported functional impairment, to address this issue.