To gain understanding on the functional role of arabinoxylans in bread-making, low molecular weight arabinoxylan (LMW-AX), isolated from a commercial wheat-derived product, and high molecular weight arabinoxylan (HMW-AX), isolated from wheat flour as such, were thoroughly characterized and tested for their impact on dough and bread-making in two European wheat flours. Dough development characteristics, as assessed by mixography, were affected considerably by the addition of HMW-AX and, to a lesser extent, by LMW-AX. Small-scale bread-making tests showed that neither water-holding capacity nor oxidative gelation or viscosity was the main factor governing LMW-AX functionality in bread-making. These findings imply that other mechanisms dictate the impact of LMW-AX and probably also of HMW-AX in bread-making. Keywords: Wheat; arabinoxylan; low molecular weight; bread-making