Purpose: The purpose of this study was to examine the effect of PBL on self-directed learning and critical thinking disposition. Method: The research design was a nonequivalent control group pretest-posttest design using two groups of first-year students from two nursing schools in Gwangju, South Korea. PBL was conducted for one semester. Result: Significant difference was found in self-directed learning between the two groups after PBL (p<0.05). but, not in critical thinking disposition. Conclusion: The findings indicate that there is a need for paradigm shift in nursing education from the traditional teacher-centered methods to a more learner-centered approach. PBL program will facilitate the development of abilities to become self-directed in learning.