This study analyzed data from an internet-based reporting system that enabled patients and families to describe adverse events. Respondents reported missed and delayed diagnoses, treatment errors, procedural complications, health care–associated infections, and adverse drug events. Most participants did not experience prompt error disclosure but instead faced a denial of responsibility and secretive behavior, which they related to subsequent mistrust. To prevent adverse events, patients and family members suggested using systems approaches (such as universal handwashing and other infection control measures), improving care transitions between providers, ensuring supervision of trainees, and partnering with patients and families for shared decision-making. These findings underscore the importance of error disclosure, effective communication, and allowing patients to report adverse events in order to enhance safety.