This module is designed to assist users on how to use ACL as a powerful tool to audit. The module is divided into 8 Chapt ers. Chapter 1 introduces audit and information technology (IT) audit, audit assertions, audit procedures, and the relationship between audit assertions and audit procedures. Chapter 2 explains ACL in the audit, describing in brief its advantages and disadvantages. Chapter 3 assists users with using ACL. In this chapter, users will learn how to install ACL (version 9), and get familiar with the ACL menus and user interfaces. This module uses a step-by-step approach to guide users from creating a new project from ACL to viewing and modifying the table in ACL. Chapter 4 elaborates how to use ACL commands for data integrity verification. For this purpose, users will learn how to count records, total numeric fields or expression, and check for validity errors. Chapter 5 shows users how to analyse their data using the ACL command. The analyses include statistics, stratify, classify, examine the sequence, check for gaps, check for duplicates, ageing, and summarise commands. The remaining chapters cover three main accounting information systems (AIS) cycles, namely, sales and cash receipts (Chapter 6), purchase and cash payments (Chapter 7), and human resource (Chapter 8). For each cycle, cases are given for better assimilation.