The study objective of the study was to determine the effect of accounting information system on the financial performance of organizations in Uganda using a case study of Aroma Medical Centre, Kampala. The objectives were to examine the impact of computerized accounting information system on financial performance of Aroma Medical Centre. To examine the effect of manual accounting information systems on financial performance of Aroma Medical Centre and to examine the effect of internal controls on financial performance of Aroma Medical Centre. The study was conducted in Aroma Medical Centre, Mulago Kampala from 19 respondents who were the employees. The data was collected using closed ended questionnaires, the analysis took the use of descriptive statistics of mean and standard deviation and correlation analysis. The study findings indicate that there is a significant relationship between computerized accounting information systems on financial performance of Aroma Medical Centre, since the sig. value (0.048). There no significant relationship between manual accounting information systems on financial performance of commercial banks, since the sig. value (0.386). There is a significant relationship between internal controls accounting information systems on financial performance of Aroma Medical Centre, since the sig. value (0.039). The study concluded that having proper accounting systems of computerization contribute to financial performance of DFCU bank. The results also indicate that the manual accounting system usage was having a low contribution or influence to financial performance of Aroma Medical Centre. The study on the third objective concludes that the proper accounting internal systems enabled the organization to work for profitability of the organization. The study concludes that accounting information system in Aroma Medical Centre contributes to financial performance of the bank though loopholes in accounting information are viewed and seen. The study recommends that computerized accounting systems need to be enhanced, developed and improved in order to enable the organization attain its proper functionality and accountability. Computerized systems need to be enhanced with the mode of the proper software that enables proper decision making in the organizations. The organization should increase the use of accounting information in marketing decisions in bringing in new product into the market, increasing sales volume and in taking better marketing strategies. On the third objective, the management need to adequately identify and manage duties including providing means to the operations of the organization through well determined duty operations and provision of an adequate auditing mechanism for the organization.