Viet Anh Vo and his U.S.-born fiancee, Heather Pham, embraced and sobbed in the courtroom after the judge announced his preliminary injunction.
The law was meant to deter foreigners from gaining visas and citizenship through sham marriages by denying licenses to people who don't present certified copies of their birth certificates.
But U.S. District Judge Ivan Lemelle said it violates their equal protection rights as well as the fundamental right to marry.
"It treats him differently from citizens born in the United States or its territories," Lemelle said.
Vo, who goes by Victor, is a 31-old U.S. citizen who has lived in Louisiana since he was three months old, but because he was born in an Indonesian refugee camp after his parents fled Vietnam, he said neither country will certify his birth.
Vo and Pham spent thousands of dollars on their wedding before their application for a marriage license was rejected last year. They tried at three separate parishes, but were denied each time by court clerks.
His lawsuit says they went ahead with the ceremony for a marriage that still lacks legal status.
"The couple, greatly disappointed, proceeded to hold a sacramental marriage in their Catholic Church. This marriage, however, is not legally recognized by Defendants or the State of Louisiana," his court papers say.
Vo is being aided by the New Orleans Workers Center for Racial Justice and the National Immigration Law Center.