The name "South-Bauchi-West (SBW) Chadic languages" identifies a dialect cluster located in the south of Bauchi State (Nigeria), first described in (Shimizu 1978).SBW languages can be characterized as both very close and united as a whole, and heterogeneous if we compare Zaar, the southernmost and numerically most important of them on the one hand, to the rest of the 25 or so other lects on the other hand (Caron 2006; Caron 2011). One way to account for this discrepancy is to start by reconstructing their proto-language and establishing their internal classification, which can then be plotted against their history and their socio-linguistic situation. This can only be done by setting the SBW lexical stock apart from the loanwords. Once they have been set apart, the study of these loanwords provides some information which will contribute to the history of SBW languages. The present study aims at sorting out borrowings from Hausa and/or Arabic, from current neighbouring languages (Pyem, Afizere, Angas, etc.), and from languages that SBW speakers must have encountered during their migration from the Lake Chad area (Mohammadou 2004; Caron 2009). This paper aims at identifying loanwords in SBW languages with the help of the RefLex lexical database[http://www.reflex.cnrs.fr/]. This study has a twofold interest: apart from the information on the lexicon and history of SBW languages, it will be an opportunity to test the performances of the database and its associated tools.