Mexico's judicial system is overseen by the Suprema Corte de Justicia de la Nation (Avalos, 2000, p. 9). Similar to the U.S. Supreme Court, the Suprema Corte has "final appellate jurisdiction over all state and federal courts" (Avalos, 2000, p. 9). At the federal level, Mexico has both circuit and district courts (Avalos, 2000, p. 9). Mexico also has a Tax Court, Labor Court, and Military Court (Avalos, 2000, p. 10).
Under a savings clause in the 1917 Constitution, each of the thirty one states retains the power to enact its own constitution and laws, provided the laws adopted do not contradict the federal Constitution (Zamora, 2004, p.102). But the apparent analogy to the United States government and federalism falls short; Mexican federalism is generally a highly coordinated autonomy with the federal government maintaining de facto ultimate control (Zamora, 2004, p. 103).
An even more significant difference between the U.S. legal system (Louisiana notwithstanding) and Mexico is that "Mexico is a civil law country" (Olah, 2005, p. 597). But it differs from other civil law countries in that its "roots  go back to 16th century Spanish law and to Pre-Columbian indigenous law" (Avalos, 2000, p. 1). When the conquistadores conquered Mexico, they imposed a Spanish rule of law, but retained indigenous "laws and legal institutions" that did not conflict with their own legal system (Avalos, 2000,p. 1). Spain also created new laws specific to Mexico (Avalos, 2000, p. 1). Today, however, all Mexican law is derived from the Constitution enacted in 1917, the Constitucion Politica de los Estados Unidos Mexicanos (Avalos, 2000, p. 3-4).
As a civil law country, Mexico also places a great emphasis on its legislatively created law. Legislative law encompasses statutes (leyes or estatudos) and codes (codigos), and, in some instances, executive branch decrees (Zamora, 2004, p. 81). Statutes consist of regulatory laws and ordinary laws, with regulatory laws controlling in case of conflict (Zamora, 2004, p. 81). Codes are "unitary work[s] that integrate all norms of a district branch of law in a systematic, comprehensive, organized, and logical manner" (Zamora, 2004, p. 81). Codes are "definitive and self-sufficient bodies of law" (Zamora, 2004, p. 81). It is assumed that legislative law will be adequate to resolve most issues that arise; therefore, statutes and codes tend to be detailed and lengthy (Avalos, 2000, p. 12).
In Mexico, codes are drafted by legal scholars. Because codes in civil law countries are developed by legal scholars, "the 'authorities' of the civil law tradition were, and continue to be legal scholars, and not judges and lawyers" (Avalos, 2000, p. 12). Accordingly, in countries like Mexico, judges and lawyers look to treatises written by prominent scholars, called doctrina, for authority, just as judges and lawyers in this country look to case law (Avalos, 2000, p. 12). Editorial Porrua publishes a series of "doctrinal treatises by the most prominent legal scholars of Mexico" (Avalos, 2000, p. 15).
Amparo suits (or jucio de amparo) are the most important type of cases heard by federal courts (Avalos, 2000, p. 10). Amparo is unique to the Mexican legal system; there is no equivalent action elsewhere (Avalos, 2000, p. 10). Essentially it is a compellation of multiple common law actions, including the writ of habeas corpus, injunction, error, mandamus, and certiorari (Avalos, 2000, p. 10).
The doctrine of stare decisis does not exist, at least in its United States' form. In Mexico, only the legislature can create new law (Avalos, 2000, p. 12-13). The Suprema Corte and federal courts can, however, "establish formally binding precedent called 'jurisprudencia'...by having five consecutive and consistent decisions on a point of law" (Avalos, 2000, p. 13). Jurisprudencia binds the courts that established it, and lower courts. If a treatise refers to jurisprudencia, it is referring to case law, not the study of law (Avalos, 2000, p. 13).
Research on Mexican law begins with a code, or possibly a statute (Avalos, 2000, p. 14). Codes are published by private publishers, primarily Ediciones Andrade and Editorial Porrua (Avalos, 2000, p. 14). And some codes have been translated into English (Avalos, 2000, p.15). Once the proper code is located, scholars must locate the applicable doctrina, or interpretation of the law - the more renowned scholars are published by Editorial Porrua (Avalos, 2000, p. 16). Journals are also a good source for doctrina (Avalos, 2000, p. 16).
Once a researcher has identified the proper codes and doctrine, he or she should search for Suprema Corte jurisprudencia and tesis sobresalientes, important, but not binding decisions (Avalos, 2000, p. 16). Suprema Corte decisions are published in the Semanario Judicial de la Federacion, which is divided into series called Epocas (Avalos, 2000, p. 16-17). "The first four Epocas (1871-1910) are called 'juriprudencia historica'[, and have] no binding force [because] the current Constitution was not [yet adopted]" (Avalos, 2000, p. 17). The Semanario is difficult to use. Therefore, private publishers started publishing decisions "in more accessible formats" (Avalos, 2000, p. 17). Still, many Mexican trained lawyers skip researching jurisprudencia altogether because of its difficulty (Avalos, 2000, p. 18).
- Avalos, F. (2000). The Mexican Legal System, 2nd Ed. Rothman: Littleton, CO. [KGF150 .A95 2000]
- Olah, F. (2005-2006). Mexican Civil Code Annotated - Bilingual Edition (book review), Miami Inter-American Law Review, 37, pp. 597-610.
- Zamora, S., et al. (2004). Mexican Law. Oxford: Oxford University Press. [KGF327 .Z36 2004]
- Henry S. Dahl, Dahl's law dictionary = Diccionario juridico (Hein, 1992) [K52.S6 D33 1992]
- John Henry Merryman and Rogelio Perez-Perdomo, The Civil Law Tradition: An Introduction to the Legal Systems of Europe and Latin America (3rd ed., Stanford University Press, 2007) [K585 .M47 2007]
- Jorge A. Vargas, Mexican legal dictionary and desk reference (Thompson/West, 2003) [KGF102 .V37 2003]
- The Federal Civil Code of Mexico (translated by J. Vargas, Thompson/West, 2005) [KGF404.32 .A52 2005]
- Mexican commercial code annotated (translated by J. Vargas, Thompson/West, 2005) [KGF1054.31889 .V37 2005]
- Mexican law : a treatise for legal practitioners and international investors (translated by J. Vargas, Thompson/West, 1998), vols. 1-4 [ KGF333.B86 M486 1998]