Collections made by scientists from ORSTOM and during French expeditions, resulting from the cooperation of ORSTOM and the Museum national d'Histoire naturelle, in the upper bathyal zone of the Indo-West-Pacific (Madagascar, Seychelles, Indonesia, the Philippines, New Caledonia, Chesterfield Islands, Wallis and Futuna Islands) have accumulated abundant crustacean material. We have added to it the collections by various Australian, German and Soviet expeditions in regions poorly explored until now. We have studied also specimens taken by deep traps near atolls in French Polynesia and in French Antilles. We have also been able to examine almost all the Homolidae deposited in the large museums of the world, reference and unidentified collections, and thereby to prepare an account of the Hawaiian, Japanese, Indian, African, South African and American faunas. From all these collections it has been possible to revise and restructure the Homolidae world-wide. Examination of all type specimens has been necessary, as has that of all specimens mentioned in the literature; practically all references and all identifications have been verified. The Homolidae comprise now 14 genera, studied in terms of their phylogenetic affinities: eight genera already known (Homola Leach, Paromolopsis Wood-Mason, Paromola Wood-Mason, Latreillopsis Henderson, Homolochunia Doflein, Hypsophrys Wood-Mason, Homolomannia Ihle, Homologenus A. Milne Edwards) ; two former subgenera elevated to generic rank (Homolax Alcock, Moloha Barnard) ; and four new genera (Dagnaudus, lhlopsis, Yaldwynopsis , Gordonopsis). Until now quite poor in species, the family now contains in the whole 57 species : it is increased by 17 new species ; in addition, about ten uncertain species are leaven apart. In the cases of two genera considered amphi-Atlantic, Homola and Homologenus, a new taxon is described: Homola minima sp . nov. is separated from H. barbata (Fabricius), typically Mediterranean ; and Homologenus boucheti sp. nov. is separated from H. rostratus (A. Milne Edwards), from the American Atlantic. Three other new species are added to Homola : H. eldredgei , H. coriolisi and H. ranunculus. The genus Paromola is confined to some species close to P. cuvieri (Risso) and two new taxa are added: P. bathyalis and P. crosnieri. Six species are attributed to Moloha of which the former is the type species M. alcocki (Stebbing), another one the ancient Latreillopsis major of KUBO (validated) ; it is augmented by two new species, M. alisae and M. grandperrini, and also M. aff. majora. The genus Latreillopsis receives three new species : L. daviei, L. cornuta and L. antennata. The new genus lhlopsis includes, besides /. multispinosa (Ihle) (formerly in Latreillopsis), one new species, /. tirardi. A third species, H. gadaletae, is added to Homolochunia. Only one species is added to Hypsophrys, H.futuna, but the genus is certainly more diverse. Three new species, H. boucheti, H. levii and H. wallis , are described in the genus Homologenus. The genus Homolax, poorly known, is well defined. For each genus a diagnosis, an illustration of the principal characteristics and homologies, plus a key to all species are given. Each genus has been strictly redefined with respect to its type species and to all its species. For the numerous poorly known species a description or summary of characters differentiating it from the nearest taxon is presented. This systematic analysis has been made by a synthetic study of all important morphological criteria; we have reviewed all the principal arrangements and structures of Homolidae to understand their homologies and reach rigorous comparisons, notably in the nomenclature of the grooves and ornamentation of the carapace which have been often confused in the past. Some phylogenetic hypotheses are briefly presented. The place of the Homolidae in Homoloidea is commented on, with a key to the three members of the superfamily. Short remarks, which will be completed in another work, on fossil representatives are outlined. Lastly, geographic and bathymetric distribution of the genera and species are discussed. Each species is represented often with drawings and always by several photographs.