The growing importance of international commerce has profound implications related to diversity, equity, and inclusion (DEI) and the ability of organizations to not only collaborate effectively with people of different cultures but to deal with them fairly and equitably. The purpose of this chapter is to identify how differences in national culture create unintended performance bias in the treatment of individuals of disparate backgrounds. We identify the six dimensions of Hofstede’s model of national cultures, explain the nature of unintended but very real performance bias, and propose ten propositions about the implications of performance bias in the treatment of people of differing national cultures.