This previous Penal Code from 1872 was replaced in 1929. The new legal order aimed to modify the legal architecture of the Porfirio Díaz dictatorship, which was based on penal repression, to align it with the context of the constitutional guarantees and social justice proclaimed by the Mexican Revolution of 1910.

Once again, any notion of homosexuality (both male and female) was formally excluded from the document. The potential criminalization allowed by the previous code due to the vagueness of the sanctions related to 'offenses against public morality and good customs' is now technically limited solely to a prohibition of pornography. Thus, Article 536 536 (Second Book; Title 8 'Crimes against Public Morality'; Chapter I 'Offenses against Public Morality or Good Customs') mentions imprisonment and fines for those who reproduce or manufacture obscene writings, images, or objects, as well as for those who display or commercialize such obscene expressions in public.

Again, in 1931, the penal code was substituted by the one that still governs at the federal level today. However, in 1966, Article 201 (Third Book; Title 8 'Crimes against Public Morality and Good Customs'; Chapter II 'Corruption of Minors') was reformed, and for the first time, a reference to homosexuality appeared. It established imprisonment for anyone who induces or incites a minor under 18 years old to engage in 'homosexual practices.' The penalty was doubled if the act was repeated and resulted in the minor 'acquiring habits of homosexual practices.'

Finally, those last provisions that indirectly incited the criminalization of homosexuality were eliminated in the 1999 reform.

In 2019, same-sex marriage was legalised in Nuevo León, after the Supreme Court found its ban unconstitutional. It would later be codified in 2023.

In 2024, the municipality of San Nicolas de los Garza passed a ban on drag shows. The rest of Nuevo León has no known bans.

In 2020, Nuevo Leon provided legal gender recognition on the basis of self-identification, including for minors. Despite a lack of a guaranteed administrative procedure, the Civil Registry and local judiciary both enable this in practice.

There are no government restrictions placed on gender-affirming care and government guidelines for public health institutions endorse medical intervention with transgender youth. However availability proves a problem in many areas.

In 2022, Nuevo León began recognising nonbinary gender identities after granting it to a 23-year-old university student.

In 2017, gender identity became a protected characteristic from discrimination in Nuevo León.

In 2017, gender identity was added as a protected characteristic from discrimination in employment in Nuevo León.

In 2017, gender identity became a protected characteristic from discrimination in housing in Nuevo León.

Same-sex adoption is legal in Nuevo León since 2019.

Surgery on intersex infants is legal in Nuevo León.

Since 2012, LGBTIQ+ people are permitted to serve openly in the Mexican military.

NOM 253 removes targeted restrictions on blood donations from gay and bisexual men. Instead, it prohibits donations from individuals with HIV or hepatitis, their partners, and those who participate in "high-risk sexual practices," irrespective of their sexual orientation.

By unanimous vote, the Plenary of the local Congress approved a reform to article 204 of the Penal Code of the State of Nuevo León in order to sanction from two to five years in prison whoever carries out conversion practices.

Illegal with a minor under 12, ambiguous rulings observed 12-18, universally legal 18+.