One of the supporting information systems utilized in performing managerial tasks including planning, organizing, controlling, and decision-making for the better utilization of the resources available is Accounting Information Systems. The main objective of this study was to determine the effect of Accounting Information Systems on the decision-making process in the case of Addis Ababa City Electric Utility related to inventory management, Internal control system, bill collection (sales,) and financial statements. The researcher used both primary and secondary data and used explanatory research methods. The researcher used a random sampling technique and distribute questionnaires to the Addis Ababa City Electric Utility staff and used Pearson correlation and linear multiple regression to check the relationship and effect between the variables respectively. The finding of this study showed that accounting information systems have a positive and significant effect on inventory management, financial statement, bill collection, and internal control system in the decision-making process. As a result, the researcher came to the conclusion that the accounting information system significantly and favorably influences the decision-making process. For better decision-making, the study recommends businesses employ accounting information systems.