||Critical thinking is a key skill among nursing graduates in achieving success on the NCLEX-RN ® and is an essential component in nursing practice. Measuring and quantifying critical thinking skills in an effort to identify students' potential success on the NCLEX-RN ® has been the focus of previous investigations. The aim of this study was to add to this body of literature by investigating the predictability of specific variables in achieving first time success rates on the NCLEX-RN ® . The three specific variables that were included in this study were grade point average (GPA), Scholastic Aptitude Test (SAT) combined math and verbal scores, and critical thinking measured on a standardized exam. The Educational Resource Incorporated (ERI) Company has developed an assessment test intended to measure the critical thinking abilities of nursing students. The ERI RN Assessment test provides a composite score, derived from 26 subscale scores, a critical thinking composite category, comprised of six individual subscale scores, and a score for each critical thinking subscale. The overall composite score, the critical thinking composite score and each subscale score were used as the predictors in this investigation. The theoretical framework that guided this study was Perry's Scheme of Intellectual and Ethical Development. An ex-post facto study design was used to examine data from the records of 182 associate degree-nursing graduates from a small, private college in the mid-Atlantic region during the years 2005 to 2007 inclusively. An equal number of student records of those that passed the NCLEX-RN ® the first time were compared to those that failed on the first attempt. Five variables were identified as possible predictors of first-time NCLEX-RN ® success. These independent variables were the ERI RN Assessment test score, the critical thinking composite score, each of the six critical thinking subscale scores, nursing course cumulative GPA, and the SAT combined math and verbal scores. The ERI RN Assessment test and the critical thinking composite score had the largest correlation ( r = .941; p < .001). Three separate logistic regressions found the most significant predictors of first-time test takers NCLEX-RN ® success were the students' nursing GPA ( p < .001) followed by critical thinking subscale four ( p = .004) measures goal setting ability, the critical thinking subscale composite score ( p = .008) and finally the overall ERI RN Assessment score ( p = .013). The admission SAT score was not a predictor of NCLEX-RN ® outcomes in this sample. An analysis of the relationship between critical thinking, nursing GPA, combined SAT math and verbal scores and NCLEX-RN ® first time test results may provide valuable information to nursing education programs. Specifically, the findings of this study should potentially influence future curricular content and the evaluation design, pedagogical approaches and early remediation interventions for students at-risk for failure of the NCLEX-RN ® in schools of nursing.