This study evaluated the impact of nursing education on students' critical thinking abilities, as measured by the Watson-Glaser Critical Thinking Appraisal (WG). In addition, the WG and the NLN Pre-Admission Test were related to GPA and NCLEX. A sample of 108 AS and BS students at the University of Hawaii School of Nursing were tested at entry and exit. AS and BS students showed comparable improvement in critical thinking ability. NCLEX was best predicted by the GPA, which in turn summed up effects of WG and NLN. The results confirm the efficacy of nursing education in improving critical thinking skills and suggest that the GPA is more important than the WG in predicting the NCLEX. The latter effect was more prominent in the BS group. Further investigation of the role of critical thinking in nursing and academic performance is suggested.