With the adoption of a new penal code in 1886, Portugal criminalised same-sex conduct. For some of this period, there was varying formality in the criminalisation but throughout LGB people were persecuted and imprisoned.

Under Portugal’s Estado Novo dictatorship (1933–1974), LGBT people faced systematic legal and social repression. While some laws predated the regime, the dictatorship expanded and enforced them strictly. In 1852, the Penal Code criminalized “offense against modesty,” indirectly targeting homosexual acts with prison terms or fines. In 1912, homosexuality was explicitly penalized under laws against “vices against nature,” punishable with up to one year in prison and sometimes enforced “re-education” in labor colonies or correctional houses.

With the Estado Novo’s rise, repression intensified. In 1936, Decree-Law No. 26 643 created the “state of delinquency,” which allowed the authorities to punish homosexual behavior even without a proven criminal act. Special detention centers and labor colonies were established, with sentences ranging from one to six years. During the 1940s and 1950s, police surveillance intensified, targeting cruising areas in public spaces, and arrests were socially selective, focusing on lower-class individuals while elites often escaped scrutiny.

The 1954 Penal Code (Decree-Law No. 39 688) explicitly criminalized homosexuality, applying “security measures” such as confinement in asylums or labor houses and probation. Over 12,000 people were admitted to such institutions between 1933 and 1951. Political repression also leveraged these laws; for example, in 1962, the politician Júlio Fogaça was convicted for homosexual conduct. Despite some softening of social surveillance in the late 1960s, repression continued until the dictatorship’s fall.

The Estado Novo ended with the Carnation Revolution on 25 April 1974, which brought an immediate decline in political policing of LGBT people. However, the legal framework criminalizing homosexuality remained until 1982. The Penal Code reform, effective in January 1983, finally decriminalized consensual same-sex relations between adults in private, marking the official end of Estado Novo-era legal repression.

In 1852 Portugal adopted a penal code based on the Napoleonic one France saw earlier in the 19th century and did not ban homosexuality.

Individuals in Portugal can legally change their gender and name on their birth certificate.

Portugal created its modern civil registry system (Registo Civil) after the Republican revolution. From this point onward, sex on birth records was fixed and could not be legally altered.

No procedure existed to change gender in legal documents. Courts and registry offices would reject changes except in extremely rare court-ordered cases (and those usually involved intersex people assigned a different gender at birth).

Until 1995, sex reassignment surgeries were banned in Portugal.

Article 13 explicitly prohibits discriminations on the basis of sexual orientations

Sexual orientation was protected.

Same sex couples in Portugal were previously not allowed to adopt or foster children. Between 2013 and 2016 various bills were put forward and rejected by parliament.

Before the 2018 law, there were no protections for intersex infants in law from genital 'normalisation' surgery.

Portugal is not one of the 22 countries that allows trans military service.

Trans people aren't explicitly banned from joining the army, but due to discrimination and regulations that also apply to cis people, but more commonly affect trans people, they are unable to join.

There is no legislation prohibiting conversion therapy in Portugal.

Before 2005's constitutional tribunal ruling, Portugal's penal code enforced unequal ages of consent for heterosexual and homosexual sex.