Landmark Cases on ExcellentWiki - Legal Encyclopedia

ADPF 54 — Abortion of Anencephalic Fetuses

Tue, 07 Jul 2026 00:00:00 +0000

Introduction

ADPF 54 (Arguição de Descumprimento de Preceito Fundamental 54) is a landmark decision of the Supreme Federal Court (STF) that decriminalized the termination of pregnancy in cases of anencephaly (a fatal fetal condition where the brain and skull are underdeveloped). Decided on April 12, 2012, the case represents a significant development in Brazilian constitutional law regarding reproductive rights, human dignity, and the interpretation of fundamental rights.

Background

The case was filed by the National Confederation of Health Workers (CNTS) in 2004, arguing that the criminalization of abortion in cases of anencephaly violated fundamental constitutional principles, including human dignity (dignidade da pessoa humana), the right to life, the prohibition of cruel treatment, and the right to reproductive autonomy.

ADI 4277 — Same-Sex Marriage

Tue, 07 Jul 2026 00:00:00 +0000

Introduction

ADI 4.277 (Ação Direta de Inconstitucionalidade 4.277), decided jointly with ADPF 132 on May 5, 2011, is the landmark decision in which the Supreme Federal Court (STF) recognized same-sex stable unions (união estável) as family entities entitled to full legal protection. The decision fundamentally transformed Brazilian family law, establishing that discrimination based on sexual orientation violates the constitutional principles of equality and human dignity.

Background

The case was filed by the Attorney General’s Office (Procuradoria-Geral da República), arguing that Article 1,723 of the Civil Code — which defined stable unions as relationships between a man and a woman — was unconstitutional for excluding same-sex couples. Simultaneously, ADPF 132, filed by the State of Rio de Janeiro, raised similar issues regarding the application of the state civil service statute.

HC 124306 — Unconstitutionality of Automatic Pre-Trial Detention

Tue, 07 Jul 2026 00:00:00 +0000

Introduction

HC 124.306 (Habeas Corpus 124.306) is a landmark decision of the Supreme Federal Court (STF) regarding the scope of the presumption of innocence (presunção de inocência) and the constitutionality of automatic pre-trial detention following a conviction at first instance. Decided in 2016, the case resolved a long-standing controversy about whether criminal defendants could be imprisoned before all appeals were exhausted.

Background

Brazilian criminal procedure had historically allowed pre-trial detention after a conviction was affirmed on appeal, based on the interpretation that the presumption of innocence did not bar imprisonment once the defendant had been properly convicted. The Penal Code and the Criminal Procedure Code (CPP) allowed enforcement of sentences after first instance conviction in certain circumstances.

RE 878694 — Unconstitutionality of Paternity Denial

Tue, 07 Jul 2026 00:00:00 +0000

Introduction

RE 878.694 (Recurso Extraordinário 878.694), with General Repercussion Theme 649, is a landmark decision of the Supreme Federal Court (STF) regarding the constitutional prohibition of discrimination between biological and socio-affective paternity in succession matters. Decided in 2016, the case established that the constitutional principle of equality among children (Article 227, §6) forbids any legal distinction based on the type of filiation relationship.

Background

The case involved a succession dispute where a child sought to inherit from a father with whom she had a socio-affective relationship (paternidade socioafetiva) — a parent-child relationship based on emotional bonds and social recognition rather than biological descent. The lower courts had denied the claim, distinguishing between biological and socio-affective paternity for succession purposes.

RE 574962 — ICMS Exclusion from PIS/COFINS Base

Tue, 07 Jul 2026 00:00:00 +0000

Introduction

RE 574.962 (Recurso Extraordinário 574.962), with General Repercussion Theme 190, is one of the most significant tax law decisions of the Supreme Federal Court (STF). Decided in 2017, the case held that the ICMS (state value-added tax on goods and services) should be excluded from the calculation base of PIS and COFINS (federal social contributions on revenues). The decision had enormous fiscal impact, potentially reducing federal tax revenues by billions of reais.

ADPF 130 — Press Law Unconstitutionality

Tue, 07 Jul 2026 00:00:00 +0000

Introduction

ADPF 130 (Arguição de Descumprimento de Preceito Fundamental 130), decided by the Supreme Federal Court (STF) on April 30, 2009, is one of the most important decisions on freedom of expression and freedom of the press in Brazilian constitutional history. The STF declared the 1967 Press Law (Law 5.250/1967) — enacted during the military dictatorship — entirely unconstitutional, holding that the 1988 Constitution had fully revoked the repressive framework of the press legislation.

MS 26603 — Impeachment of Dilma Rousseff and Separation of Powers

Tue, 07 Jul 2026 00:00:00 +0000

Introduction

MS 26.603 (Mandado de Segurança 26.603) is a pivotal decision of the Supreme Federal Court (STF) concerning the impeachment process of President Dilma Rousseff in 2016. The case addressed fundamental questions of separation of powers, the scope of congressional authority in impeachment proceedings, and the role of the judiciary in reviewing political processes. It established important limits on the STF’s intervention in impeachment while protecting procedural due process.

Background

In 2015-2016, President Dilma Rousseff faced impeachment proceedings based on allegations of fiscal mismanagement — specifically, that her administration had used unauthorized loans from public banks to finance government programs (“fiscal pedaling”). The process was initiated in the Chamber of Deputies and subsequently proceeded to the Federal Senate.

HC 143641 — House Arrest for Pregnant Women

Tue, 07 Jul 2026 00:00:00 +0000

Introduction

HC 143.641 (Habeas Corpus 143.641) is a landmark decision of the Supreme Federal Court (STF) recognizing the right of pregnant women and mothers of young children to house arrest (prisão domiciliar) in place of pre-trial detention. Decided in 2018, the case represents a significant development in Brazilian criminal procedure, applying constitutional and international human rights principles to address the specific vulnerabilities of women in the criminal justice system.

Background

The case was a collective habeas corpus petition filed by the Public Defender’s Office (Defensoria Pública) on behalf of all pregnant women, postpartum women, and mothers of children under 12 years of age who were in pre-trial detention. The petition argued that pre-trial detention of these women violated their rights and the best interests of their children.