The aim of the present paper is to sketch a state of the art regarding the Bua languages of Chad, a genetically related linguistic group that remains relatively little-known. Section 1 presents and lists the different languages that belong to this genetic unit. A historical review of the documentation is presented in Section 2. Section 3 lays out a lexicostatistical approach to the internal relationships of the languages, complemented by some other discriminating features. Some salient phonological and morphological features are discussed in Section 4 that gives a particular attention to the crucial noun class system of Kulaal. Section 5 deals with problems of comparison, correspondences and reconstruction within the Group. Lastly a word will be said about the current Bua languages comparative project in Section 6.