Objective: To compare the performance on the American Board of Ophthalmology Written Qualifying Examination (WQE) with the performance on step 1 of the United States Medical Licensing Examination (USMLE) and the Ophthalmic Knowledge Assessment Program (OKAP) examination for residents in multiple residency programs. Design: Comparative case series. Participants: Fifteen residency programs with 339 total residents participated in this study. The data were extracted from the 5-year American Board of Ophthalmology report to each participating program in 2009 and included residency graduating classes from 2003 through 2007. Residents were included if data were available for the USMLE, OKAP examination in ophthalmology years 1 through 3, and the WQE score. Residents were excluded if one or more of the test scores were not available. Methods: Two-sample t tests, logistic regression analysis, and receiver operating characteristic (ROC) curves were used to examine the association of the various tests (USMLE, OKAP examination year 1, OKAP examination year 2, OKAP examination year 3, and maximum OKAP examination score) as a predictor for a passing or failing grade on the WQE. Main Outcome Measures: The primary outcome measure of this study was first time pass rate for the WQE. Results: Using ROC analysis, the OKAP examination taken at the third year of ophthalmology residency best predicted performance on the WQE. For the OKAP examination taken during the third year of residency, the probability of passing the WQE was at least 80% for a score of 35 or higher and at least 95% for a score of 72 or higher. Conclusions: The OKAP examination, especially in the third year of residency, can be useful to residents to predict the likelihood of success on the high-stakes WQE examination. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.