This article describes the development of the Nursing Incivility Scale (NIS), which is designed to assess hospital nurses' experiences with incivility according to specific sources-physicians, coworkers, patients, and direct supervisors. The NIS was developed using focus groups with nurses at a hospital in the midwestern United States and validated during a second survey administered to 163 hospital nurses. Exploratory factor analysis revealed that the NIS items grouped according to a priori scale construction. All subscales showed acceptable reliability and demonstrated acceptable convergent and discriminant validity with other variables. The results indicate that the NIS has good psychometric qualities and can be used by hospitals and health care administrators to assess the prevalence of incivility.