The presence of Mexican law - as the applicable foreign law - continues to grow considerably in American courts. This phenomenon is significant in California and the southwestern states, as well as in Illinois, New York and Washington, D.C. It is unquestionable that deciding cases based on Mexican law poses a challenge especially to judges but also to legal practitioners. As a result of this increasing trend, special attention is being given by American law schools to include in their curricula general courses on Mexican law or specialized seminars addressing specific areas of Mexican law such as contracts, torts or enforcement of judgments (some of them taught in Spanish). This descriptive article provides the most complete and current introduction to Mexico's legal system. The article is divided into six parts: Part One informs about Mexico as a country and then discusses Mexico's three federal powers: the legislative, the executive and the judicial. Part Two offers a thorough explanation of the Sources of the Law in that country, from the Federal Constitution of 1917, to statutes and codes, and others, including the role of Jurisprudencia. Part Three describes the federal and state court systems. The Americanization of Mexican law and the intriguing and sui generis Amparo are discussed in Parts Four and Five, respectively. Part Six is a most practical addition: it consists of a current list (in the Spanish language) of the Best Mexican Law Web Sites available in the Internet, sponsored by that country's federal government and by its 32 federal legal entities, providing free and easy access to some five hundred federal statutes and regulations, including all of the Mexican federal codes, as well as all of the state codes and state legislation. Indeed, this wealth of legal statutes, codes, regulations and international treaties and conventions constitute, in the opinion of this author, the best Mexican law library in the world.