This study aims to analyze the influence of whistleblowing System, internal control system, organizational culture, and organizational justice, on fraud prevention. The sample in this study were the civil servants of irrigation department of aceh province who have been working at least five years. This Study uses primary data collected using questionnaires. In this study, sample of 198 respondents were selected using purposive sampling. The analytical tool used in this study is SPSS 24. Based on the result of data analysis is showing that whistleblowing System has no effect on fraud prevention. Internal control system, organizational culture, and organizational justice has significant positive effect on fraud prevention.