In her films Trintignant has focused on family and relationships, often borrowing from her own life. Much of her work took place during the 1970s, a time of great advancement for woman filmmakers in France. Trintignant's interest in feminist issues and the perils of the heterosexual couple can be seen in many of her films, such as "Mon amour, Mon amour" (1967) and "Le voyage des noces" (1976). In 1971 she signed the Manifesto of the 343, published in the French magazine Le Nouvel Observateur. The article was signed by 343 women who admitted to having had abortions in order to end the ban on abortion and raise awareness of female reproductive rights.