Studies have shown diagnostic discordance in evaluation of surgical pathology specimens. In this study, pathologists and pathology residents were asked to diagnose surgical pathology or cytopathology cases and provide a diagnosis. Most respondents provided the correct diagnosis for most of the cases; 35% of cases were wholly or partially misdiagnosed. Educational and process changes (e.g., requiring subspecialist over-read for some diagnoses) were implemented in the pathology department in response, resulting in substantial improvement in error rates.