Using a social projection paradigm, the present study investigated offenders' beliefs that "everyone breaks the law." A modified Tolerance for Law Violations Scale (TLV) was completed by 103 male provincial prison inmates and 135 male nonoffenders. Participants subsequently estimated either the percentage of offenders or nonoffenders who would agree with their responses to each of the 10 items that compose the TLV. As predicted, offenders scored significantly higher on the TLV than nonoffenders, indicating that offenders are more likely to see law violations as acceptable behavior. In addition, offenders significantly overestimated the actual percentage of offenders and nonoffenders who would endorse criminal sentiments and behaviors; that is, offenders believed that criminal conduct was normative behavior for not only offenders but for nonoffenders as well. Implications of the findings are discussed in terms of social norms theory and social norms intervention within a prison setting. (Published Abstract)