This research study has examined all possible areas of the study was conducted on Auditing procedure and internal control system with reference to Union Bank of Nigeria Plc. However, the areas where the research revolves around are not limited to the scope of the study. Audition procedure and internal control system is very important in every organization to identify the loopholes and lapses to proffer lasting solution. Data was analyzed using descriptive and chi-square statistics for test of hypotheses. The five point likert scale will be used analyze the data for the study. The research questions will be analyzed using the percentage analysis. For hypotheses testing, chi-square statistics will be used to test the individual hypothesis formulated. Its also important to posit that internal audit ensure detention of financial fraud and irregularities. In the course of the research work, its discovered that organization with effective internal audit system are more likely to affect fraud than organizations with no such system and function. Adequate internal audit system must be established in the organization to ensure that activities of the organization are carried out effectively and should be provision of adequate training programme to the staff of Lagos State University. Also, qualified and competent staff should be employed in other to ensure efficient operation.