Purpose: The purpose of this study was to identify self-efficacy, disposition to critical thinking and level of nursing competency in new nurses and to exam the correlation among these variables. Method: The sample was composed of 286 new nurses who had worked at E hospital for 1 year. Descriptive and correlation analysis using the SPSS program were used to analyze the data. Results: The mean score for self-efficacy was 67.10, disposition to critical thinking, 3.01 and nursing competency, 3.02. There were significant differences in scores for 3 variables between nurses with College degrees and nurses with Baccalaureate degrees. There was a significant positive correlation between disposition to critical thinking and nursing competency scores. Conclusion: Further study of the various components that influence nursing competency is necessary. Also based on the disposition to critical thinking, there is a need to develop education programs to strengthen curiosity and other related variables. The results of this study confirmed the necessity of developing a clinical model of nursing competency ability.