Road headers and other cutting machines are often used for excavation in the mining and tunnelling industries. During excavation, changes in the properties of the rock mass can alter which adversely impact machine performance. Also it has also been found that an estimation of machine performance differs from that actually achieved in the field. It has been postulated that one reason for this variation in performance could be due to a rock’s moisture content. This paper outlines the results of a study that examined the impact on rock cutting performance of changes in the moisture content of sandstone. The study found both cutting and normal forces decreased with moisture content by up to 40 and 49% respectively when cutting a saturated sample compared to the dry rock sample. Reductions were also found in specific energy, cutter pick wear and some other rock properties.