Abstract: The study was conducted to evaluate the effect of internal audit on the performance of the URSB. A cross-sectional survey design was adopted by the study and a mixed methods approach for data collection and analysis was used. The data was collected using questionnaires and structured interviews. A sample of 152 respondents was used and a total of 142 was accessed giving a response rate of 92.1%. The study findings established a weak statistically significant relationship between Internal audits and Performance of the URSB (r = 0.329; p< 0.05 (=0.000). Furthermore, regression results established that internal audit accounts for 10.1% of the variance in performance of URSB. In conclusion, internal audit reflects gaps that need to be attended to boost the performance of the URSB. In order to improve the performance of the Uganda Registration Services Bureau, it is recommended that management of URSB ensure that Budgetary controls are given top priority in order to promote cost-effective procurement, boost surplus income, and save money. Furthermore, the management must strengthen the implementation of internal audit and the segregation of duties.