Introduction: The evaluation of Florida Primary Care Physicians' knowledge with the most common misdiagnoses and the possible impact of Continuing Medical Education (CME) classes on that knowledge will prove beneficial to physicians and health care personnel concerned with quality control and education of proper practices in the health care setting.Methods: An anonymous survey was created and sent via email to 551 licensed Internal Medicine and Family Practice physicians. The questions tested physician's knowledge of the most common misdiagnoses and the breakdown points resulting in misdiagnoses. The Rasch model was used to analyze subject's responses. The survey was sent to 551 physicians, 179 of whom responded. Of those who responded, 47.5% have a private practice, 71% are over the age of 45, and 90% are Board certified. The majority of physicians surveyed (55.4%) had over 16 years in practice. These figures mirror those of the general physician population in the state of Florida. Results: Of the 179 physicians (32.5% response rate) who completed the survey, 40% correctly identified Pulmonary Embolism as the most commonly misdiagnosed condition (in terms of relative incidence) but only 7% of physicians correctly identified infections as the most common misdiagnosis (in terms of total incidence). Interestingly, 58% of physicians understood that breast cancer is the most commonly misdiagnosed, which leads to malpractice. Conclusion: Most physicians are not aware of the most common misdiagnosis or of the most common process errors, which lead to misdiagnoses. Yet, physicians seem to be better informed about misdiagnoses that commonly lead to malpractice. This may be a result of physician bias, or a deficiency on the part of continuing medical education courses to present empirical material on the most common misdiagnosed conditions.