Before developing interventions for stomatitis, nurses require a simple, valid and reliable approach to staging severity. The eight-item WCCNR was previously validated for chemotherapy-induced stomatitis. In this study, the validity and reliability of the WCCNRR, a shorter three-item tool for staging stomatitis caused by chemotherapy, radiotherapy, or both, was assessed. Pairs of data collectors evaluated 207 patients from 10 Canadian cancer centres. The WCCNRR correlated well with the MacDibbs Mouth Assessment (r=0.44, p=0.0002 to r=0.54, pR is a valid and reasonably reliable tool for staging stomatitis due to cancer therapy.