[4] His first novels, Un simple and Bonne Dame, published in 1891,[5] were naturalistic works about provincial mores.
[6] His next novel, L'Empreinte (1896), a satire of life at a Jesuit college, was based on his education and reflected Estaunié's anticlerical views.
[5] After his first three works, Estaunié's novels began to focus on everything that is silenced and unspoken in his characters' lives.
[6] In this period, spiritual phenomena, such as "the soul, the 'secret life', and solitude", were "the dominating realities in Estaunié's universe"[7] In 1908, his novel La Vie secrète won the Prix Femina.
He was elected to the Académie française on 15 November 1923, taking the chair formerly occupied by Alfred Capus.