A close friend and collaborator with the avant-garde director Patrice Chéreau, the two created groundbreaking work together at both the La MaMa Experimental Theatre Club in New York City and the Théâtre des Amandiers in Nanterre.
By chance Hubert Gignoux, the director of the National Theater of Strasbourg, attended the show on opening night and was instantly enamored of Koltès's work.
He directed some of his own work there, including La Marche (The Walk), an adaptation of the biblical Song of Solomon, and Procès ivre (Drunken Trial), based on Fyodor Dostoevsky's Crime and Punishment.
Some of Koltès's early works such as L'Héritage (The Inheritance) and the unpublished Des Voix sourdes (Deaf Voices) were even broadcast on national French radio in 1972 and 1973.
His first widely celebrated piece, the long monologue, The Night Just Before The Forests, was staged in 1977 at the Avignon Festival, and subsequent productions were put on in collaboration with director Patrice Chéreau.