Usually, fraud occurs under the skin of firms and who live on that organizational level, most probably are aware of the occurrence of that, whether evidence is weak or not. If aware people whistle-blow the occurrence of fraud, the imposition of extreme loss on a firm and society, could be prevented. The purpose of this research is to investigate why this kind of people are inactive. The population of this research consisted of master students entering 2014 (included students from Tehran, Allameh Tabataba'I, and Tarbiat Modares universities), accountants, and auditors, and during the 2016 year, have been collected 126 questionnaires for examining the hypothesis. Participants who read the scenario answered questions, and then have been examined hypothesis by path analysis. The results show that evidence strength and perceived responsibility have a positive significant effect on the likelihood of reporting. When there is strong evidence, people feel more responsible and more probably will report fraud anonymously. The result of this research can help us to improve our understanding of workplace, to promote fraud identification, and to prevent its occurrence.