ASHINGTON, Jan. 10 - The Supreme Court refused on Monday to hear a challenge to a Florida law that prohibits gay men and lesbians from adopting children.

Florida's is the only such statute in the country, and the prohibition is the only categorical adoption ban on the state's books. Florida evaluates adoption applications from all other would-be adoptive parents, including those who have failed at previous adoptions and those with a history of drug abuse or domestic violence, on a case-by-case basis.

Three gay men and the children they have raised in long-term foster care challenged the statute in a lawsuit filed four years before the Supreme Court, in Lawrence v. Texas, invalidated that state's criminal sodomy law in a landmark gay-rights ruling.

The Florida plaintiffs had lost their case in Federal District Court in Key West and had already filed their briefs with the federal appeals court in Atlanta when the Lawrence decision was issued in June 2003. Their lawyers then filed supplemental briefs arguing that the Texas decision meant that Florida's law should also fall, as an expression of anti-gay sentiment that the Supreme Court had ruled could not be a basis for public policy.

But a three-judge panel of the United States Court of Appeals for the 11th Circuit disagreed, ruling last January that the Lawrence decision did not refute "the accumulated wisdom of several millennia of human experience" that the "optimal family structure" in which to raise children was one with a mother and father married to each other.

The appeals court then deadlocked 6 to 6 on whether the full court should rehear the case. The rehearing request failed because a rehearing requires a majority vote. One of the judges voting against rehearing the case was William H. Pryor Jr., who was named to the appeals court as a temporary recess appointment by President Bush during an 11-day Congressional recess last February. Had Judge Pryor not participated, the appeals court would have reconsidered the case.

The validity of the Pryor appointment - whether the president's constitutional authority to make appointments "during the recess of the Senate" to positions ordinarily requiring Senate confirmation applies to such short recesses - is the subject of a separate case that has been appealed to the Supreme Court.

Although Florida's adoption law had contained a preference for married couples, the state repealed that provision in 2003. One-quarter of the adoptions in the state are by single people.

The state Legislature voted to prohibit adoptions by gays in 1977, in the midst of a campaign led by the entertainer Anita Bryant to repeal a gay-rights ordinance adopted by Dade County. The state senator who sponsored the adoption measure, Curtis Peterson, said at the time that its purpose was to send a message to the gay community that "we're really tired of you" and "we wish you'd go back into the closet."

Florida permits gay men and lesbians to be foster parents. The lead plaintiff in the case, Steven Lofton, is a licensed foster parent who has taken in eight children with H.I.V. or AIDS, winning an award as the outstanding foster parent of the year from the agency that placed the children in the home he has shared for 20 years with his partner, Roger Croteau. The boy identified in the case as John Doe, now 13, has been with the couple since infancy.

The Supreme Court made no comment Monday in turning down the case, Lofton v. Secretary of the Florida Department of Children and Families, No. 04-478. The justices may have decided to permit the Lawrence decision to play out in different contexts in various courts before taking up the gay rights issue once again.

Matthew A. Coles, director of the Lesbian and Gay Rights Project of the American Civil Liberties Union, which represented the plaintiffs, said in an interview that the fact that the Florida law was unique might have limited the court's interest in the case.

Last month in Arkansas, in another suit brought by the A.C.L.U., a state trial judge struck down a law that prohibits placing foster children in a household with a gay adult. Arkansas has announced that it will appeal the ruling. Mr. Coles said the Arkansas case might be the next to reach the Supreme Court.

In another Supreme Court development on Monday, lawyers for Zacarias Moussaoui, the only person charged in an American court with conspiring in the Sept. 11 attacks, filed an appeal of a ruling last April that restored the government's right to seek the death penalty while at the same time limiting Mr. Moussaoui's right to seek testimony from captured members of Al Qaeda who have told interrogators that he had nothing to do with the plot.

A federal district judge, Leonie V. Brinkema, ruled in 2003 that without giving Mr. Moussaoui access to favorable witnesses, the government could not seek the death penalty. The United States Court of Appeals for the Fourth Circuit, in Richmond, overturned that decision last April, holding that Mr. Moussaoui's right to favorable testimony could be preserved through written summaries rather than direct access to the witnesses, who are being held overseas as enemy combatants.

The Supreme Court appeal, Moussaoui v. United States, was filed under seal because the record contains classified material. One of the lawyers for Mr. Moussaoui, Edward B. MacMahon Jr., described the case as one that concerns "the most fundamental rights of a criminal defendant to mount a defense." The court is expected to make a public version of the petition available next week.