The Cognitive Autopsy is a novel strategy towards understanding medical error and diagnostic failure in 42 clinical cases with which the author was directly involved or became aware of at the time. Essentially, it describes a cognitive approach towards root cause analysis of medical adverse events or near misses. Whereas root cause analysis typically focuses on the observable and measurable aspects of adverse events, the cognitive autopsy attempts to identify covert cognitive processes that may have contributed to outcomes. In this clinical setting, no cognitive process is directly observable but must be inferred from the behavior of the individual clinician. The book illustrates unequivocally that chief among these cognitive processes are cognitive biases and other flaws in decision making, rather than knowledge deficits.