Yes, judicial review in Mexico is a well-established feature of the constitutional system. The Constitution gives federal courts three distinct tools to test whether laws, regulations, administrative acts, and even court rulings comply with the Constitution and with the human rights treaties Mexico has signed. Which tool applies depends on who is complaining and what they want the court to do.
State courts generally cannot strike down laws on constitutional grounds. That authority sits with the federal judiciary, which makes Mexico’s system more centralized than the United States model readers may be used to.
The Three Mechanisms at a Glance
Articles 103 and 107 of the Constitution create the juicio de amparo, the vehicle individuals use to challenge government action. Article 105 creates two mechanisms reserved for government entities and certain officeholders: the controversia constitucional, which resolves jurisdictional disputes between branches or levels of government, and the acción de inconstitucionalidad, which can erase an unconstitutional law from the books entirely.
The practical differences matter. An amparo protects the person who files it. A constitutional controversy sorts out which government body holds a disputed power. An action of unconstitutionality is the only route that removes a law from the legal order for everyone.
Juicio de Amparo: The Individual’s Tool
The juicio de amparo (roughly, “protection suit”) is the most widely used form of judicial review in Mexico. Any person who believes a government action or omission has violated their constitutional or human rights can file one. It works both as a shield against unconstitutional laws and as a remedy for abusive government conduct, covering situations as varied as wrongful detention and an agency’s refusal to act on a permit.
Amparo proceedings come in two tracks. A direct amparo challenges a final judgment from a court or labor tribunal and is filed before a collegiate circuit court. An indirect amparo targets laws, regulations, administrative acts, or government conduct that is not a final court ruling, and it begins before a federal district court. Procedural rules, deadlines, and available remedies differ between the two.
The Relativity Principle
An amparo ruling traditionally applies only to the person who brought the case. This is the “Otero formula,” or relativity principle. If a court finds a law unconstitutional in an amparo proceeding, the law is simply not applied to the winning plaintiff. It stays on the books and continues to apply to everyone else. Removing an unconstitutional law from the legal system entirely requires a different tool.
Limits on Suspension Orders
One of the amparo’s most powerful features has been the ability of a federal judge to suspend a challenged law or government action while the case is pending. In the past, some judges issued suspensions that froze enforcement of entire laws for the general population, not just for the plaintiff. A June 2024 amendment to Articles 129 and 148 of the Amparo Law ended that practice. Federal judges are now expressly prohibited from issuing suspensions with general effects when an amparo challenges the constitutionality of a law. The suspension protects only the individual plaintiff, and the challenged law remains in force for everyone else until the case is decided on the merits.
Controversia Constitucional: Disputes Between Governments
The controversia constitucional resolves turf wars between branches and levels of government. When a federal agency encroaches on a state’s authority, or when two branches of a state government disagree about which one holds a particular power, the aggrieved entity can bring the dispute directly to the Supreme Court of Justice of the Nation (SCJN).
Standing is limited to government actors: the federal executive and legislative branches, state governments, municipal governments, autonomous constitutional bodies, and the government of Mexico City. The question is always whether one governmental body has overstepped its constitutional boundaries and invaded another’s jurisdiction.
Constitutional controversies can challenge individual government acts and general norms like laws or regulations, with one notable exception: electoral matters are excluded entirely.1Portal de Estadística Judicial @lex. Preguntas frecuentes – Controversias Constitucionales When the SCJN rules in a constitutional controversy and the decision reaches the required supermajority, the invalidated norm ceases to apply generally, not just between the parties.
Acción de Inconstitucionalidad: Striking Down Laws
The acción de inconstitucionalidad is the mechanism built to remove unconstitutional laws from the legal system. It targets the law itself rather than protecting an individual, and its effects are general.
Only a narrow set of actors can file. Under Article 105, standing belongs to a minority bloc of at least 33% of the legislators in the body that passed the challenged law, the Attorney General, political parties registered to compete in elections, and human rights commissions at the federal and state level. The action must be filed directly with the SCJN within 30 calendar days after the challenged law or treaty is officially published.
If the SCJN declares the law unconstitutional by a supermajority, the norm is struck down with general effects and removed from the legal order. Before the 2024 reform, that required at least eight votes out of eleven justices. After the Court was reduced to nine seats, the threshold is now six of nine.2Judiciaries Worldwide. Mexico – Section: Federal Judiciary
Human Rights Treaties as Part of the Benchmark
A 2011 constitutional reform expanded what counts as a constitutional question. Amended Article 1 provides that every person in Mexico enjoys the human rights recognized in the Constitution and in international treaties to which Mexico is a party. Courts must interpret these rights using whichever source gives the individual the broadest protection. This interpretive mandate is the principio pro persona.
In practice, a federal judge reviewing a government action under an amparo is not limited to the text of the Mexican Constitution. The judge must also consider protections in treaties like the American Convention on Human Rights and apply whichever standard is more favorable to the claimant. The SCJN has described constitutional and treaty-based rights not as a hierarchy but as an integrated body of norms, all of which form the benchmark for evaluating government action. The exception is when the Constitution itself expressly restricts a right; the constitutional restriction then controls.
Mexican courts are also required to conduct control de convencionalidad, a duty to check on their own initiative whether domestic law conforms to the American Convention on Human Rights. The obligation stems from the Inter-American Court of Human Rights’ ruling against Mexico in the Radilla Pacheco case, and failing to perform the review can itself constitute a treaty violation. Judicial review in Mexico therefore operates on two tracks at once: constitutional compliance and treaty compliance.
How Rulings Become Binding: Jurisprudencia
Mexico sits in the civil law tradition, which traditionally gives less weight to judicial decisions than common law systems do. But Mexico has developed a system of binding precedent, called jurisprudencia, that gives judicial review real force. When the SCJN or certain lower federal courts interpret a constitutional provision in a qualifying ruling, that interpretation binds all courts in the country.
The Supreme Court can create binding precedent through several paths. A plenary decision approved by at least eight votes, or four votes in a chamber, on a constitutional question binds every court in Mexico, federal and state alike. Decisions in constitutional controversies and actions of unconstitutionality also become binding jurisprudencia when they reach the required vote threshold.3Suprema Corte de Justicia de la Nación. Constitutional Precedent in the Mexican Supreme Court When lower federal courts issue conflicting interpretations on the same question, the SCJN resolves the contradiction and its resolution becomes binding precedent too.
Before a 2021 reform, the SCJN generally needed five consistent rulings on the same issue before an interpretation became binding. That reiteration requirement was eliminated for Supreme Court decisions, which now create binding precedent from a single qualifying ruling. The change accelerated the Court’s ability to settle constitutional questions.
What the 2024 Reform Changed
In September 2024, Mexico enacted its most sweeping judicial reform since 1994. The three mechanisms of judicial review remain intact as legal tools. The Constitution still guarantees amparo, constitutional controversies, and actions of unconstitutionality. What changed is the institutional setting in which judges exercise them.
Federal judges, including Supreme Court justices, circuit magistrates, and district judges, are now chosen by popular vote. The SCJN was reduced from eleven justices to nine, and terms were shortened from fifteen years to twelve with no reelection. The smaller bench changes the vote math: six of nine is now enough to strike down a law in an action of unconstitutionality, down from eight of eleven.
The reform also dissolved the Federal Judiciary Council and created a Judicial Discipline Tribunal (Tribunal de Disciplina Judicial) to oversee the conduct of judicial officials. The tribunal can review judicial decisions, reverse them, and remove or sanction judges whose rulings it considers out of line. Its members are themselves elected. Critics say this introduces political control over judicial decision-making because the power to discipline judges for their rulings creates pressure to align with prevailing political currents. Supporters say it provides accountability for a judiciary that historically operated with minimal oversight. For judicial review, the practical effect is that judges striking down government action now do so under the eye of a politically elected disciplinary body that did not previously exist.