Objective: Dentists play an important role in the early diagnosis and treatment of oral lesions. However, treatment based solely on a clinical impression of the diagnosis, without histologic confirmation, can result in serious consequences, particularly when the lesion is precancerous or cancerous. The purpose of this study was to determine the overall accuracy of clinical diagnoses made by dentists as well as to compare the diagnostic ability of general practitioners with members of various dental specialties. Method and Materials: The biopsy reports of 976 specimens submitted to the Department of Oral and Maxillofacial Pathology, Virginia Commonwealth University School of Dentistry, between January 2009 and January 2010 were reviewed. The presumptive clinical diagnosis made by the practitioner and the final histologic diagnosis on each specimen were recorded in addition to whether the submitting dentist was a general practitioner or a specialist. Results: Of the clinical diagnoses made by the submitting dentists, 43% were incorrect. General dentists misdiagnosed 45.9%, oral and maxillofacial surgeons 42.8%, endodontists 42.2%, and periodontists 41.2% of the time. The most commonly missed clinical diagnoses were hyperkeratosis (16%), focal inflammatory fibrous hyperplasia (10%), fibroma (8%), periapical granuloma (7%), and radicular cyst (6%). Cancerous lesions were misdiagnosed 5.6% of the time. Conclusions: The high rates of clinical misdiagnosis by dental practitioners indicate that all excised lesions should to be submitted for histologic diagnosis. Keywords: cancer diagnosis, clinical misdiagnosis, diagnostic accuracy