Using a proprietary data set from a provider of internal whistleblowing (WB) systems, we analyze nearly two million internal WB reports submitted to over 1,000 publicly traded U.S. firms. We provide descriptive statistics, over time and across report types, on the amount and summary details of information provided, how extensively management reviews reports, the amount of time until reviews were completed, and the outcome of these reviews. Further, we examine the characteristics of firms with more actively used systems (i.e., a higher volume of reports, more information provided in reports, and reports that are more frequently reviewed by management). Finally, we show that internal WB report volume is associated with fewer and lower amounts of government fines and material lawsuits. JEL codes: G34; G38; M41; M42; M54