A research report submitted for partial fulfillment of the requirements for the degree of Accounting and Finance in the Business sector of Mzumbe UniversityThe effectiveness of an internal control system within any organization is crucial in determining the performance of that organization not only in internal processes but also in external market dynamics from customers as well as competitors. The purpose of this study is to take a look at the effects of internal control on the performance of manufacturing industries. Specifically, the study intended to identify the reliability of internal control components as used by the organization, to assess the organization's performance and to establish the relationship between the internal control components and performance of the organization. A sample size of 25 respondents from different departments of TBL was used in this study. Both primary data and secondary data was collected using a questionnaire, interviews, observations, and documentary review. SPSS was used to analyze data and presented by using tables. The findings of the study show that the most reliable component of internal control is monitoring while the least reliable is control activities. The study also found that the best performance measure is customer services and product market performance. Correlation analysis between internal control components and performance of auditing indicated that the control environment is most positively correlated with the effective and efficient of the audit while it has a negative correlation with agreement of the final audit objectives. The study recommends that firms should come up with other strategies aimed at making the employee more aware of the internal control components especially by improving areas related to meet the three objectives of internal control which are ensuring service quality, reliability of reporting (better audit quality) and ensure legal compliance (conformance to TBL policy)