This report, the second in a series from the United Kingdom's National Patient Safety Agency, analyzes nearly 45,000 patient safety incidents relating to mental health that were reported to a nationwide incident reporting system. The majority of reported incidents were from inpatient mental health facilities, primarily involving patient accidents (including falls), disruptive or aggressive behavior, self-harming behavior, and missing (absconding) patients. The report summarizes existing initiatives to improve patient safety in mental health, makes specific recommendations for mental health providers, and identifies priority areas for future research.