He has written a seminal work on Greek mythology entitled Homosexuality in Greek Myth, translated into English two years later by Beacon Press. In 1986, he followed up with a study covering early homosexuality in Europe, under the title of L'homosexualité initiatique dans l'Europe ancienne, which has yet to be translated into English. The two studies have been published together, with a postface, as Homosexualité et initiation chez les peuples indo-européens. In Genèse de L'Inde, he attacks the recent anti-invasionist reconstructions of early Indian history. Instead he defends the traditional hypothesis that the Indo-Aryans came into India in the 2nd millennium BC. According to Sergent, the Dravidian populations are not autochthonous either, but of African origin. The book Les Indo-Européens - Histoire, langues, mythes is a general introduction to the Indo-European language family. Sergent associates the Indo-European language family with certain archaeological cultures in Southern Russia, and he reconstructs an Indo-European religion. In the monograph, Les trois fonctions indo-européennes en Grèce ancienne, vol. 1: De Mycènes aux Tragique, Sergent examines the employment of the Dumézilian tripartite system in Greekepic, lyric and dramatic poetry. In a second volume, which has not been published yet, he will continue this examination with Greek philosophy and religion. His recent work, Celtes et Grecs, is dedicated to comparative Greek and Celtic mythology. In volume 1, Le livre de héros, the Irish hero Cuchulainn is compared with the Greek heroes Achilleus, Bellerophon and Melanthius and the Irish epic Táin Bó Cúailnge with the Greek Iliad, which, according to Sergent, presuppose an Indo-European "pre-Iliad". In volume 2, Le livre des dieux, Sergent argues that the Celtic and Greek pantheons derive from a common Indo-European inheritance.
Works
L'homosexualité initiatique dans l'Europe ancienne, Payot 1986
Les Indo-Européens Payot, 1995
Genèse de l'Inde, Payot, Paris 1997
De Mycènes aux Tragique, Économica 1998
Celtes et Grecs, Payot, 1999
La guerre à la culture: aspects des attaques contre l'intelligence dans la période jospino-raffininesque, L'Harmattan, 2005,
Les Dragons. Mythes, rites et légendes, 2018, Fouesnant-Embanner, 2018