A self-taught filmmaker, Mona Achache worked as an assistant director and then as a script supervisor on fiction and documentary films. After making two short films and a documentary, in 2009 she made her feature-length directorial debut with The Hedgehog, a film loosely based on Muriel Barbery's novel Elegance of the Hedgehog. The film was released in France and more than thirty other countries. Her second feature, Les Gazelles, was released in 2013. Achache has directed around twenty television films, documentaries, and episodes of series for TF1, France 2, Arte, and Netflix. Her latest film, Little Girl Blue, starring Marion Cotillard, is inspired by the life and writings of her mother, Carole Achache, and was presented as a Special Screening at the Festival de Cannes in 2023.