The interest in the Sabellian languages, i.e. Oscan, Umbrian and remaining central Italian dialects, attested in inscription from the Italian peninsula appr. 650 - 50 BCE, is ever increasing. With the discovery of new inscriptions and new interpretations of already known text, the understanding and contextualisation of these pre-Roman languages becomes ever more detailed. Following in the wake of recent editions, and the 'Worterbuch des Oskisch-Umbrischen' by Jurgen Untermann (2000), this study is the first step in the direction of a complete Sabellian grammar. Focusing on the case system, the volume compiles and explains all the various grammatical constructions attested. Including both an introduction to phonology and a detailed summary of the morphology of the case endings, the extant linguistic material, although scarce, is highlighted and discussed, on both an internal and external comparative level, with an historical perspective concerning the development and uses of the constructions.