This Article addresses the challenges, trends, and evolution of Taxpayers’ Rights both in the Unites States and in Latin America, particularly by comparing the U.S. Taxpayers’ Bill of Rights and the recently adopted Taxpayers’ Rights Letter from the Latin American Institute of Tax Law (ILADT). Furthermore, although in Latin American this is a relatively more recent topic, nonetheless, in the United States it is not, and the Article also addresses the evolution of taxpayers’ rights both from the point of view of the U.S. Constitution as well as iconic decisions from the U.S. Supreme Court.