There is widespread agreement that many neuropsychological measures do not have acceptable diagnostic accuracy when used among people who are not Caucasian, welleducated, native English-speaking, and middle to upper class (Ardila et al. 2002; Boone et al. 2007; Brickman et al. 2006; Loewenstein et al. 1994; Manly 2005). A review of scholarly works reveals that not only is this an area of controversy in our field, but also that neuropsychological testing among culturally and linguistically diverse people is an area of critical vulnerability in the theoretical and empirical foundation for neuropsychological practice. The current status of neuropsychological practice among culturally and linguistically diverse people raises ethical questions. Guidelines for ethical decision-making within the neuropsychological assessment of ethnically and linguistically diverse people has been discussed in detail in several prior publications (Artiola i Fortuny & Mullaney 1997; Brickman et al. 2006; Harris et al. 2002; Wong 2006), making ethics one of the more comprehensively documented “subtopics” in cultural neuropsychology. The American Psychological Association Ethics Code (“Ethical Principles of Psychologists and Code of Conduct” 2002) states that it is unethical to use inappropriate measures among culturally different individuals. Yet, refusing to assess a large and growing segment of the population, many of whom may potentially benefit from neuropsychological services, would also violate the ethics of our field (Brickman et al. 2006; Harris et al. 2002). It is our ethical obligation to safeguard the welfare of people who come under our care, to take cultural background into account and to do our best to eliminate bias (“Ethical Principles of Psychologists and Code of Conduct” 2002). The quality and accuracy of current assessment of culturally diverse people may be “the very best we can do” but whether this level of practice is justified entirely depends on the setting of the assessment, what is at stake, the evidence base for the methods used, and the level of cultural competency of the neuropsychologist. Despite recent proliferation in the number of publications that directly address ethical, theoretical, and practical issues in cultural neuropsychology, the explosive growth in the number of culturally and linguistically diverse people in the United States has exposed our lack of preparation. We are playing a game of catch-up that is, in part, responsive to the pressure of a national research agenda of reducing health disparities in the United States. Cognitive function has been implicated as a critical predictor and outcome of gaps in health across the lifecourse (see Glymour and Manly, this issue), and therefore accurate assessment is crucial in addressing these disparities. The facts on America’s growing cultural diversity are essential knowledge for neuropsychologists in the in the United States. Although 66% of the population is nonHispanic White in 2008, this “majority” group will contribute far less of the total population growth in coming years. The non-Hispanic White share of the U.S. population has fallen steadily from 74% in 1995 to 66 percent in 2008, Neuropsychol Rev (2008) 18:179–183 DOI 10.1007/s11065-008-9068-8