This article reviews factors related to adverse events in relation to adult congenital heart disease (ACHD). Adults with ACHD are becoming a rapidly increasing proportion of the adult medical and surgical population. The authors reviewed closed medical malpractice claims from 1970 to 2001 from the Anesthesia Closed Claims Program. This article describes the contribution of perioperative risk factors to adverse outcomes as well as comparing contributing factors in cardiac versus non-cardiac operations. All cases were assessed separately for factors contributing to the adverse event and factors contributing to patient injury. Qualitative assessments are also presented and common themes across the cases reviewed.