But wedding bells will not soon be ringing for gay couples in the Lone Star state because the judges stayed execution of his injunction pending an expected appeal.
Judge Orlando Garcia ruled the ban had no “rational relationship to a legitimate government purpose” and violated the constitutional guarantee of equal protection under the law.
“Equal protection is at the heart of our legal system and is essential for the existence of a free society,” Garcia wrote in a 48-page opinion.
Texas Governor Rick Perry was quick to denounce the decision and vowed to “fight for the rights of Texas to self-determine the laws of our state.”
“Texans spoke loud and clear by overwhelmingly voting to define marriage as a union between a man and a woman in our Constitution, and it is not the role of the federal government to overturn the will of our citizens,” he said.
The decision comes as the state of Michigan is in court defending its gay marriage ban.
Federal judges in Virginia, Utah, Oklahoma, Ohio and Kentucky have recently ruled in favor of marriage for lesbian and gay couples, as has the New Mexico Supreme Court.
The rulings follow a landmark Supreme Court decision in June finding that couples in same-sex marriages were entitled to the same benefits and protections as their heterosexual counterparts.
Marriage laws are governed by individual US states, nearly 30 of which have amended their constitutions to ban same-sex marriage.
Efforts to give same-sex couples the same rights as heterosexuals have gathered steam in recent years in the US.
Support for gay marriage has seen dramatic gains in the United States over the past decade and now has the support of a majority of Americans, a study released Wednesday showed.
The survey by the non-partisan Public Religion Research Institute found that 53 percent of Americans said they are in favor of gay marriage.
That number reflects a 21-point jump compared to 2003, when 32 percent of people said they supported same-sex marriage.