There is a consensus in the safety field that organizations must use multiple methods of detecting errors and adverse events, as individual approaches vary in their ability to identify different types of safety issues. Rapid response systems (RRSs) have been widely deployed to detect and stabilize deteriorating hospitalized patients, and this study investigated whether analysis of RRS activations could be used to identify preventable hazards. Systematic review of patients seen by the RRS revealed that almost 20% had experienced an adverse event, 80% of these were preventable, and most were not reported to the institution's incident reporting system. Hospitals should consider formal review of RRS activation as a trigger for identifying adverse events.