Diagnosis is an uncertain art. Four areas of our reasoning cause misdiagnosis. The first two are use of outdated information and faulty data collection, and can be easily corrected. The third area is incomplete knowledge and requires constant continuing education. The fourth area is flaws in clinical reasoning and is due to being ignorant of one's own ignorance. It is the hardest area to improve and requires constant thinking about one’s thinking. This interactive session will review the clinical reasoning that we can employ to reach a diagnosis by using straightforward, challenging and difficult rabbit cases.