Problem Statement and Background: While the psychometric properties of Objective Structured Clinical Examinations (OSCEs) have been studied, their latent structures have not been well characterized. This study examines a factor analytic model of a comprehensive OSCE and addresses implications for measurement of clinical performance. Methods: An exploratory maximum likelihood factor analysis with a Promax rotation was used to derive latent structures for the OSCE. Results: A model with two correlated factors fit the data well. The first factor was related to Physical Examination and History-Taking was labeled as information gathering, while the second factor was related to Differential Diagnosis/Clinical Reasoning, and Patient Interaction and was labeled as reasoning and information dissemination. Case Management did not contribute to either factor. The factors accounted for a total 61.6% of the variance in the skills variables. Conclusions: Recognizing the psychometric components of OSCEs may support and enhance the use of OSCEs for measuring clinical competency of medical students.