[3] She played Sandra Benzakhem in the 1997 film La Vérité si je mens !, for which she was nominated for a César Award for Most Promising Actress.

[5][6] Casar portrayed Myriem in How I Killed My Father (2001) by Anne Fontaine;[7] Assia Wevill in Sylvia (2003) by Christine Jeffs;[8] the lead role of The Woman in the Catherine Breillat erotic film Anatomy of Hell (2004);[2][9] and Eva in To Paint or Make Love (2005) by Arnaud and Jean-Marie Larrieu, which was nominated for the Palme d'Or at the 2005 Cannes Film Festival.

[13] In 2007, Casar appeared in installation artist Sophie Calle's Venice Biennale piece Prenez soin de vous (Take Care of Yourself).

[2] In 2008, she played Dolorès in Laetitia Masson's Coupable [fr],[14] and portrayed Irene in Werner Schroeter's last film, Nuit de chien.

[19][20] In 2013, she appeared in the Arnaud des Pallières film Michael Kohlhaas,[21][22] and portrayed Anne-Marie Munoz in Bertrand Bonello's Saint Laurent in 2014.