At age 19, after studying at a Catholic Jesuit school in Cairo, Sinoué went to France to study at the national music conservatory in Paris. He became skilled in classical guitar. He later taught classical guitar to others and started writing. In 1987, at about age 40, he published his first novel, La Pourpre et l’olivier, ou Calixte 1er le pape oublié (The Crimson and the Olive Tree, or Calixte I the Forgotten Pope). It earned the Jean d’Heurs prize for best historical novel. In 1989, he published Avicenne ou La route d'Ispahan, relating the life of Avicenna (Abu Ali Ibn Sina in Arabic), the Persian doctor, philosopher and scientist.
His novels and other books span a variety of genres. Sinoué's third novel The Egyptian is the first of a saga set in Egypt of the 18th and 19th centuries. Published in 1991, this novel won the literary prize Quartier latin. In the biography L'ambassadrice (2002), Sinoué relates the life of Emma, Lady Hamilton.
In 2004 his thriller Les Silences de Dieu (The Silences of God) won le Grand prix de littérature policière (Grand Prize for Mystery/Detective Literature).
Gilbert Sinoué quickly established himself as an engaging storyteller and master of a variety of genres. His biography, The last phar'aoh, depicts the battle of Mehmet Ali, the pacha, with the Ottoman empire. In the thriller Le Livre de Saphir (The Sapphire Book), the narrator converses with God.
In addition to writing books, Gilbert Sinoué is a scriptwriter and screenwriter.