Hospitals are being encouraged to engage patients in safety programs, in part because prior studies have shown that patients themselves can be a unique source of information about adverse events. In Sweden, clinicians are required to report cases of serious adverse events, and patients can obtain compensation for such events through a no-fault malpractice insurance system. However, this study found that more than 80% of cases where patients were compensated for severe injuries were not reported by practitioners, including many cases of health care–associated infections and diagnostic errors. The related editorial calls for hospitals to redouble their efforts to promote patient participation in reporting and addressing patient safety problems.