This chapter examines the use of IDEA, which is the second most commonly used generalized audit software in use. Like ACL, it is a powerful tool for a nontechnical auditor to examine data in detail from a variety of sources with a variety of standard audit tests and present the results in a range of high-impact presentation formats. This chapter assumes that readers have downloaded the software and data files of the demo version at https://ideasupport.caseware.com/public/downloadidea/.