To identify prepharmacy variables that predicted graduate performance on the North American Pharmacist Licensure Examination (NAPLEX) test. Undergraduate and pharmacy school transcripts for 424 students admitted to the Texas Tech University Health Sciences Center (TTUHSC) Doctor of Pharmacy program from the fall of 1996 to the fall of 2001 were reviewed. NAPLEX scores were provided by the Texas State Board of Pharmacy (TSBP). Statistical analyses were performed using SPSS, 11.5. Grade point average, composite Pharmacy College Admission Test (PCAT) score, and California Critical Thinking Skills Test (CCTST) score were each positively correlated with NAPLEX score (p < 0.001 for each). Type of school where organic chemistry was completed; age; advanced courses taken in chemistry, biology, and math; and attainment of a BS, BA, or MS degree were not significantly correlated with NAPLEX score (p > 0.05). When comparing students who successfully graduated and passed the NAPLEX with students who were academically suspended or who failed the NAPLEX, there were significant differences in mean PCAT scores, CCTST score, and age (p < 0.05 for all). Stepwise regression analysis applying all admission variables except PCAT subscores revealed a correlation between predictors (composite PCAT, prepharmacy GPA, and age) and NAPLEX score (p < 0.001). Composite PCAT score was the strongest predictor of success and failure on the NAPLEX. However, the combined predictive ability of PCAT and CCTST scores, prepharmacy GPA, and age was relatively low. Thus, a full review of each candidate's application is justified.