Mexico's Supreme Court ruled last week that a law banning gay marriages in the southern state of Oaxaca state was unconstitutional, paving the way for gay couples to marry in that state and in the rest of the country.
The tribunal dismissed the law that declared the purpose of marriage was to "prolong the species."
The court also said in its ruling that conditioning marriage unions to those between a man and a woman "violated the principle of equality."
Activists see the law as part of a sea change in attitudes on homosexuality in Latin America.
The powerful Catholic hierarchy in Mexico calls gay marriage immoral.
On Sunday (December 9), the gay community in Oaxaca celebrated by draping themselves in a large rainbow flag outside the Santo Domingo Church in the middle of Oaxaca City.