The government's integrated financial management information system is essential to improve fraud prevention in Nigeria. One of the most challenging obstacles confronting government sector has always been fraud prevention. According to studies, the integrated financial management information system has aided government budget planning, execution, and monitoring, as well as tracking, recording, and reporting revenues and expenditures in government offices and parastatals in other developing economies, in order to close any gaps and reduce the risk of fraud. The study examined the effect of government integrated management information system on fraud prevention in Nigerian. Survey design was adopted. One hundred and Thirty-Seven (137) copies of questionnaires were administered to government employees in the selected agencies and one hundred and thirty-three (133) were returned. Descriptive and inferential (Multiple regression) were used to analyse the data. The result of the finding shows that integrated financial management information has significant effect on fraud prevention in Nigerian public sector. Adj. R 2 = 0.64, F-statistics 35.862, P-value <0.000. The study concluded that integrated financial management information system has significant effect on fraud management. The study recommended that the federal government should maintain the integrated financial management system so that when power changes, they will continue to use the system that is already in place to avoid stagnating economic growth and development.