PURPOSE: This investigation examined the effect of PBL on the meta-cognition, critical thinking, and problem solving process. METHOD: The research design was pre-posttest with a nonequivalent control group design. Scenarios for PBL sessions were developed on the basis of textbooks and patients' charts and tested for content validity. Seventy six nursing students who took a 'Nursing Process' course from two nursing schools participated in the experimental group and control group. The experimental group performed PBL during the semester. Meta-cognition and problem solving processes were assessed by questionnaires which were developed using pedagogics. Critical thinking was measured by the CCTST(California Critical Thinking Skill Test) Form 2000. The data was analyzed by repeated measure (pretest-posttest) MANOVA, and correlation analysis. RESULT: PBL improved the participants' meta-cognition and problem solving process but not critical thinking. The relationship between meta-cognition and the problem solving process was supported but the relationship between critical thinking and problem solving was not supported. CONCLUSION: These results suggest that PBL has a positive effect on nursing students' educational outcomes. To improve the problem solving ability of nursing students, PBL should be applied to more subjects in the nursing curriculum.