The second edition of this widely read patient safety primer, written by a national leader in the field and a past recipient of the John M. Eisenberg Award, is nearly twice the length of the first. The new edition continues to blend case studies with broad discussions of error types and strategies to improve safety but adds substantial new content in areas such as checklists, measures of harm (including trigger tools), information technology, complexity theory and high reliability, policy initiatives in patient safety, and balancing "no blame" and accountability.