This chapter examines the ethics and business diplomacy of tax minimization through tax avoidance or tax sheltering by multinational enterprises (MNEs). This focus excludes state-owned enterprises (SOEs) and purely domestic businesses. The chapter uses the terms business and corporation interchangeably for MNEs. Also, business diplomacy and corporate diplomacy are basically the same; business ethics and corporate ethics are basically the same. Ethics denotes a rationale for accepting a moral obligation not required by law. (There is a general moral obligation to obey the law, but civil disobedience doctrine provides a basis for disobeying immoral laws.) Acceptance might be strictly voluntary, in the sense that executives and directors wish to be ethical, fair, and just; or responsive, willingly or grudgingly, to stakeholder and social expectations, in the sense of corporate social responsiveness. A growing body of literature calls for nonavoidance behavior by businesses on ethical or responsibility arguments. That is, ethical and responsible businesses willingly should pay taxes beyond legal requirements. The usual rationale is the desperate social need for tax revenues. This set of arguments will be termed corporate tax responsibility (CTR), as a special category within business ethics and corporate social responsibility (CSR). Business diplomacy involves a broader commitment to the public good. In addition to assessing the ethical and responsibility literature on nonavoidance behavior, this chapter explores the business diplomacy strategy of nonavoidance behavior. In general terms, business diplomacy in an international business environment of multiple stakeholders, of variable power and importance to an MNE, concerns maximizing corporate legitimacy through responsiveness to social public demand in order to improve the public good (Ordeix-Rigo & Duarte, 2009; Wolters, 2012). Stakeholder views of tax policy and tax compliance involve variable conceptions of fairness and burden (Chittenden & Foster, 2008).