Only four senators voted against the law, while 130 voted in favour. After the king's signature, the law will come into effect in 120 days, allowing Thai same-sex couples to get married. This makes Thailand the first country in Southeast Asia to introduce same-sex marriage. Two other Asian countries, Taiwan and Nepal, already recognise the right to marriage regardless of gender.

The law defines marriage as a union between two individuals, regardless of gender. Married couples will also be able to adopt children. All major parties in parliament expressed their support for opening up marriage during the 2023 election campaign. In 2020, the Supreme Court declared a legal provision that marriage could only be between a man and a woman unconstitutional, after which the effort to introduce same-sex marriage gained momentum.