The context of this research is that there are still many cases of fraud that occur in companies, central government, local authorities or public institutions. The purpose of this study is to determine whether and to what extent internal audit and good governance play a role in preventing fraud in Moroccan public enterprise. The independent variable is "internal audit" and "good governance," while the dependent variable is "fraud prevention." We adopted a post-positivist posture, a hypothetico-deductive logic and a quantitative approach. The research population is made up of internal auditors, a total of 35 people in Moroccan public enterprise. We used a non-probability sampling technique, more precisely, the saturated sample technique, and then multiple regression to model fraud prevention and its determinants. The results of the study show that internal audit and good governance have a positive and significant role in fraud prevention. In addition, internal audit and good governance contribute 49.2% in the prevention of fraud.