After her studies, Badinter taught at the École Polytechnique. Her first book titled, L'Amour en plus, was published in 1980 and raises the question of whether maternal love is an exclusively natural instinct or a tendency reinforced in the cultural context, in which the behaviour of motherly affection is expected.
In her critical work, L'un est l'autre, published in 1987, Badinter reflects upon the complementarities of masculin and feminine traits in gendered identities and the conflicts that arise when these complementarities are subjected to oppression. Badinter concludes that a new era of gendered resemblances will lead to a change in gender identities and a revolution of moral values.
During the 1989 Islamic scarf controversy in France, Badinter, Régis Debray, Alain Finkielkraut, Elisabeth de Fontenay and Catherine Kintzler wrote an open letter to the then Minister of Education, Lionel Jospin, demanding to not let students who refuse to take off their headscarves go to school. Badinter believes that the French public education system should be free of any religious affiliation and that neutrality in public institutions of a secularist state must prevail over expressions of individuality in them.
Her 2003 treatise, La fausse route, addresses misandry and victimisation of women by French contemporary feminists. "The systematic denial of women's power and violence, the constant portrayal of women as oppressed and therefore innocent is deepening the crevasses of a divided humanity: the victims of masculine oppression on one side and the Almighty executioners on the other. "
She is best known for her philosophical treatises on feminism and women's role in society. She is an advocate of liberal feminism and women migrant workers's rights in France. A 2010 Marianne news magazine poll named her France's "most influential intellectual", primarily on the basis of her books on women's rights and motherhood.
Badinter is the largest shareholder of Publicis Groupe, a multinational advertising and public relations company, and the chairwoman of its supervisory board. According to Forbes, she is one of the wealthiest French citizens with a fortune of around US$1.8 billion in 2012.