Critical thinking is an important concept in nursing education and is thought to be necessary for success in nursing. The primary purpose of this study was to determine if critical thinking is predictive of success in a nursing program. Success was defined as passing the National Council of State Boards of Nursing licensing exam for registered Nurses (NCLEX-RN) on the first attempt. This study used an alternate measure of critical thinking, the Collegiate Assessment of Academic Proficiency (CAAP) critical thinking test. Multiple linear regression analysis was performed using passing the NCLEX-RN as the dependent variable and using critical thinking scores, GPA in nursing, and GPA in science courses as the independent variables. Results indicated that critical thinking scores were not predictive of success. Binary logistic regression analysis was performed to corroborate results and similar results were found. The student's GPA in nursing courses was, however, found to be a statistically significant predictor of success.