Fraud has been identified as the major cause of distress and unprogressive nature of most business organisation in the country. Even though, there are intelligent people who work round the clock to fault the system; but there are more intelligent people who build on fraud check devices hence the computer. It is the aim of this study to find out the role of computer in fraud detection and prevention in business organization (A Case study of First Bank of Nigeria Plc.) The work has five chapters, chapter one contains the body of the topic which included the problems studied, why the study was carried out and the definition of terms. An extensive review of related literature on computer as it relates computer crime, types, Computer fraud, Types, role of Computer in fraud detection and prevention are highlighted in chapter two. Chapter three dealt with the design of the study, the methods used in the distribution and collection of the questionnaires and the treatment of the data. The data got from the research survey were analyzed interpreted and the hypothesis tested in chapter four. Finally, the summary of findings, conclusion on the research and recommendation are all in chapter five. If Banks and other business organisations in the country would put the findings and recommendations to use, the incessant incidence of fraud will not only be detected and prevented but the customers will be satisfied with the services, which will bring a continuos increase in profit there by making the problem of the banks a thing of the past..