Geoplanidae comprises approximately 900 species and is divided into four subfamilies: Bipaliinae Stimpson, 1857 (cosmopolitan), Geoplaninae Stimpson, 1857 (neotropical), Microplaninae Pantin, 1853 (cosmopolitan), and Rhynchodeminae Graff, 1896 (cosmopolitan). A substantial part of the taxonomic studies of land planarians from South American dealt with species from the East of the Andes, especially from the southern and southeastern regions of Brazil, and from Argentina. The diversity of Geoplanidae from West of the Andes, such as Chile, is still little known. The 28 known species described from Chile belong to Rhynchodeminae (1), Timyminae (2) and Geoplaninae (25). Within Geoplaninae, the 14 species of the genera Geoplana, Pasipha and Pseudogeoplana have uncertain taxonomic position. The other species are housed in the genera Gusana (2); Liana (1), Pichidamas (1), Inakayalia (3) and Polycladus (1), all endemic, except Inakayalia, which occurs in the Argentinean Andes. In this thesis, the morphological and molecular studies of 20 recently collected specimens resulted in