Detecting adverse events remains a challenge across health care settings. This prospective study conducted in multiple pediatric inpatient settings used medical record review, clinician reports, and hospital incident reports to identify adverse events. Investigators compared adverse events detected with these mechanisms to adverse events identified through interviews with parents and caregivers of pediatric patients. As with previous studies, two physicians reviewed all incidents and rated the severity and preventability of all incidents. About half the incidents reported by family members were determined to be safety concerns; fewer than 10% of these incidents were felt to be preventable adverse events. Family-reported error rates were similar to error rates drawn from actively eliciting error reports from clinicians. Families were able to identify preventable adverse events that were not detected by any other method. Error rates calculated from hospital incident reports were much lower than those drawn from either clinician or family reports, consistent with prior studies. These results demonstrate that families can identify otherwise undetected adverse events and their input should be elicited in safety surveillance systems.