Arabinoxylans (AX) from cereals are cell wall components that constitute an important part of the dietary fiber intake in humans. Enzymatic hydrolysis of AX yields arabinoxylan-oligosaccharides (AXOS), consisting of arabinoxylooligosaccharides and xylooligosaccharides (XOS). This reaction takes place in the production of AXOS and of cereal-derived food products such as bread and beer, as well as in the colon upon ingestion of AX. This review mainly focuses on the available evidence that AXOS and XOS exert prebiotic effects in the colon of humans and animals through selective stimulation of beneficial intestinal microbiota. In addition, in vitro experiments and in vivo intervention studies on animals or humans are discussed that have investigated potential health-related effects resulting from the dietary intake of AX, AXOS, or XOS.