The European Court of Human Rights has ruled that France discriminated against a lesbian nursery school teacher by refusing to let her adopt a child.
The judges decided that the woman was a victim of discrimination because of her sexual orientation.
They said her right to family life under the European Convention on Human Rights had also been infringed. France has been told to pay her damages.
Nine European countries allow homosexuals to adopt children.
The court's ruling in Strasbourg on Tuesday noted that: "French law allowed single persons to adopt a child, thereby opening up the possibility of adoption by a single homosexual."
The court criticised the French judiciary's emphasis on "the lack of a paternal referent in the household" in the case of the lesbian woman, who was identified only as E.B.
The reference to the applicant's homosexuality had been "if not explicit, at least implicit," the ruling said.
The case came before the court in Strasbourg in December 2002.
A spokesman for the court said it was the first such ruling against one of the 47 members of the Council of Europe, which set up the court.
Ten judges voted in favour of the ruling and seven against.
The court told France to pay the woman damages of 10,000 euros (£7,446; $14,522) and 14,528 euros in costs.