These fifteen, pre-1450 cartularies coming from Cistercian communities located in present-day Walloon territory, either cartularies preserved in their original form or copies of cartularies known in indirect fashion, are presented one after the other. Material study of the manuscripts and analysis of their contents sometimes allow us to distinguish several phases in the compilation of these cartularies. This examination has above all allowed us to confirm that no Cistercian cartularisation policy existed: the abbeys, even those either geographically close or by filiation, did not have the same practices in the field of copying charters, and/or bulls, in specific books. Thus, all of these cartularies had as their primary goal conserving the memory of the most important acts of each abbey, but while some are manuscripts of prestige, others are in a greatly reduced format, containing far fewer colours, and written in a much less bookish style… and in fact seem to be more working manuscripts. It is also particularly interesting to observe that monks who worked on elaborating a manuscript of prestige seem to have very quickly crafted another, or other, more manipulable, manuscript(s) in basing themselves on the prestigious manuscript.