Violence and victimization inside the prison setting are accepted as facts, although the facts about their prevalence remain uncertain. Variation in the methods used to estimate rates of sexual and physical victimization contribute to the wide range in estimates appearing in the prison literature. This article focuses on the questions used in the prison victimization literature to elicit information on victimization from inmates, compared to questions used in the general victimization literature. The questions used in the National Violence Against Women and Men Surveys are used to estimate sexual and physical victimization rates for an entire prison system. Rates of victimization were found to vary significantly by specificity of the question, definition of perpetrator, and clustering of behaviors. Facts about victimization inside prison will become more certain when the methodology becomes more standardized and consistent with definitions of victimization. (Contains 4 tables.)