Seventy-six species of terrestrial isopods are recorded from Corsica. Eight species (Oritoniscus punctatus, Tiroloscia montana, Platyarthrus corsicus , Cylisticus uncinatus, Alloschizidium campanellii, Armadillidium lanzai, A. littorale and A. torchiai ) are described as new and twelve are newly recorded from the island. The subspecies Oritoniscus paganus paganus Racovitza and O. paganus ocellatus Vandel are raised to species rank. Phalloniscus pygmaeus (Budde-Lund) is transferred to the genus Sardoniscus Arcangeli, and Paraschizidium remyi Vandel and Typhloschizidium cottarellii Argano & Pesce to the genus Alloschizidium Verhoeff, of which Typhloschizidium Arcangeli and Nesolidium Verhoeff are considered to be junior synonyms. About half of the species have a West-Mediterranean distribution, the majority being strictly Tyrrhenian (38%). About 25% of the species are endemic, which demonstrates the importance of Corsica as a speciation area. The oniscidean fauna of Corsica is strictly related to that of the Tuscan Archipelago and, to a lesser extent, to that of Sardinia. Some important faunistic affinities exist with southern France (massifs of Maures and Estérel, and the Grasse region) and the Pyrénées. No species of southern origin (Sicilian or North African) has been collected in Corsica, which seems to exclude a zoogeographic relationship with those regions. The distribution of the species within Corsica is discussed. A key to all the species is given.