Financial performance is a critical turning point for prosperity of any financial institution. Many Accounting Information system (AIS) have been adopted and used to ensure effectiveness on financial performance. Currently, most organizations continue to increase spending on information system and their budgets continue to rise. Accounting Information system (AIS) provides financial institutions like SACCOs an orderly, efficient scheme for providing accurate financial information and controls. This normally has effects on the financial performance of an institution, either positively or negatively. This research work sought to examine the effects of accounting information system, on financial performance of SACCOs in Nyeri County. Specifically, the research sought to: establish the effect of financial reporting systems on financial performance of Saccos in Nyeri County; determine the effect of inventory management systems on financial performance of the Saccos in Nyeri County; and find out the effect of budgetary control systems on the financial performance of Saccos, in Nyeri County. The research findings provided knowledge on the financial performance of the SACCOs based on the AIS integration, since AIS effects have not been extensively assessed, the concept of AIS being one of the latest innovations. The research was of key importance to the Saccos as well as other financial institutions in terms of determining the benefits accruing due to the integration of accounting information systems in their operations. A pilot test was conducted to ensure the tool’s validity and reliability. Statistical Packages for the Social Sciences version 24 was used to analyze data using descriptive analysis and inferential statistics. Ethics were followed before, during and after the study was completed. Descriptive research design was used in this research whose target population was the over 180 employees of the six (6) SACCOs identified in Nyeri County, where a sample size of 9 employees was sampled per SACCO using stratified random sampling. Data was collected using both secondary and primary data collection methods. Primary data collection tools were self-administered questionnaires, while journals, text books, and internet were used to collect secondary data. Data analyzed was presented using frequency tables, bar charts and graphs. The study concluded that a strong significant relationship exists between financial reporting systems and financial performance of saccos in Nyeri County, Kenya. The study also concluded that there was a strong significant relationship between inventory management systems and financial performance of saccos in Nyeri County, Kenya. The study went further to conclude that a strong significant relationship exists between budgetary control systems and financial performance in Nyeri County, Kenya. As a result of the clear relationships established between variables the study was able to conclude that a clear relationship exists between accounting information systems and financial performance of saccos in Nyeri County, Kenya. The study recommends the Government to develop policies and guidelines that will encourage Saccos to adopt accounting information systems, as well as Institute of Certified Public Accountants of Kenya to offer consultation services to saccos on choosing appropriate accounting systems, financial management and reporting