This paper assesses the impact of the Americans with Disabilities Act (ADA) on preemployment psychological testing. The paper discusses rules and related guidelines of the Equal Employment Opportunity Commission (EEOC) and relevant case law under the Rehabilitation Act. EEOC rulings clarify the scope of what is intended to be included in the definition of mental impairment, indicating that the only limitation on the use of any preemployment psychological test is that the test may not disclose a mental or psychological disorder. The definitive resource on what constitutes a mental or psychological disorder is the "Diagnostic and Statistical Manual of Mental Disorders" (Third Edition, Revised). Tests or scales whose purpose is to disclose an impairment may only be used after a conditional offer of employment has been made. However, tests used to assess personality traits, behavior, attitudes, or propensity to act, when these are not symptoms of a mental disorder, may be used at the pre-offer stage. As commonly used psychological tests are not medical in nature and are not utilized to identify disabilities when used for employment screening, the specific time when such tests may be administered is not controlled by the ADA. (JDD)