As the number of older persons in the U.S. increases there is also an increase in incidence of dementia. Neuropsychologists, because of their role in the assessment of cognitive functioning, will see more aged patients and face many related ethical concerns. Ethical concerns involved in the disclosure of a diagnosis of dementia have produced considerable debate. This paper will discuss a number of issues that may affect the neuropsychologist's decision to disclose a dementia diagnosis. Topics discussed include the impact of the patient's mental capacity and awareness of cognitive deficits on the decision process; respect for the autonomy of the patient; the ethical responsibility to “do no harm”; the sometimes-competing wishes of the patient and their caregivers and the impact of not telling the truth. Also discussed are some advantages of disclosing diagnoses to patients and suggestions on the best strategies for disclosing a dementia diagnosis.