The Court of Cassation, France's top civil court, ruled on Tuesday that in vitro fertilization, though illegal for gay parents in France, is not enough to prevent their legal right to adopt.
By making the ruling the court is validating France's landmark 2013 law which legalized gay marriage and cleared the way for same-sex couple's to adopt children.
However, some French courts had refused to carry out adoption of children who were born abroad to lesbian couples who got pregnant via in vitro fertilization.
Because French law only permits IVF for sterile heterosexual couples, some courts deemed those gay adoptions as 'fraud.'
The Cassation ruling stated, French law allows "by adoption, the establishment of a family link between a child and two people of the same sex, without any restriction relative to the mode of conception of the the child."
The ruling is advisory and not enforcable, but decisions of this type generally serve as a benchmark which is applied by lower courts across the land.
"It would be surprising if judges continue to resist this," Lawyer Florent Berdeaux-Gacogne, who represents gay couples in adoption cases, told French daily Le Figaro.
Given the pitched battle over France's legalization of gay marriage, which included violent protests, the reaction to the ruling was quick and harsh from conservatives.
"The only way to get out of this spiral is to repeal the (gay marriage) law. Any other response would be hypocritical because the law doesn't stop IVF," said National Assembly member Hervé Meriton of the centre-right UMP party. "To avoid that we need a clear political line."
Another source of controversy surrounding gay families is surrogacy, though it remains illegal for all couples in France.
However, the European Court of Human Rights ordered France in June to recognize the status of children born abroad to surrogate mothers, even though surrogacy is currently illegal in France.
While Dominique Mennesson, the heterosexual mother who brought the case, said the verdict was a "great relief", her lawyer Patrice Spinosi, told Le Figaro the case could impact on thousands of children.
"In the eyes of French law, these children have no parents, not even the father who is raising them," said Spinosi. "Two thousand children in France are in the same situation as the Mennesson girls."