The purpose of this study was to compare the Physician Assistant Clinical Knowledge Rating and Assessment Tool (PACKRAT) and the Objective Structured Clinical Examination (OSCE) as predictors of performance on the Physician Assistant National Certifying Examination (PANCE). In order to become a licensed physician assistant one must graduate from an accredited program and pass the PANCE. Physician assistant programs use several methods to evaluate students and prepare students to take the PANCE. These methods include exams such as the PACKRAT and the OSCE. Due to the fact that the PACKRAT and the OSCE are being used for this purpose, it is imperative to know the predictive value of these exams on the PANCE. Methods: The study data used in this investigation were collected on 84 WSU PA Program graduates of 2003 and 2004 who have taken the PANCE. The identified set of explanatory variables include PACKRAT I, PACKRAT II, OSCE I, OSCE II, and PANCE scores. Correlation analysis was conducted comparing PACKRAT I and PANCE, PACKRAT II and PANCE, OSCE I and PANCE, and OSCE II and PANCE using linear models to determine how the scores relate. Logistic regression was used to assess the capability of PACKRAT I, PACKRAT II, OSCE I, and OSCE II to predict the PANCE score. Results: PACKRAT and PANCE scores were shown to be highly correlated. OSCE and PANCE scores were also correlated, but to a lesser degree. Linear regression revealed a significant relationship between the PACKRAT and PANCE, with 58% of variance in PANCE scores being accounted for by the variance in PACKRAT scores. The OSCE scores accounted for 19% of variance in PANCE scores. Conclusion: Both the PACKRAT and OSCE scores were predictive of PANCE scores. The PACKRAT was more predictive of the PANCE than the OSCE.