The Georgia Supreme Court ruled unanimously that the ban did not violate the state's single-subject rule for ballot measures when it was overwhelmingly approved by Georgia voters in 2004.
Gov. Sonny Perdue had promised to call a special session of the Legislature next month if the court had not ruled by then.
Gov. Sonny Perdue, (R) Georgia, said, "I think this is the end of the line. For those who are disappointed, I'm sorry, again the process has taken place, the question was put before the General Assembly, it was passed by two-thirds of both Houses, it was put before the people."
A lawyer for LAMBDA legal defense and education fund, which challenged the constitutional amendment, was disappointed with the ruling, but he said no further legal challenge is planned.