Purpose: The purpose of this study was to identify the moderating and mediating effects of self-leadership in the relationship between organizational culture and nurses' informatics competency. Methods: Participants in this study were 297 nurses from the cities of Busan and Ulsan. The scales of organizational culture, self-leadership and informatics competency for nurses were used in this study. Descriptive statistics, Pearson correlation coefficient, stepwise multiple regression were used for data analysis. Results: Nursing informatics competency of the participants was relatively low with a mean score 3.02. There were significant positive correlations between subcategories of perceived organizational culture, self-leadership and nursing informatics competency. Self-leadership was a moderator and a mediator between organizational culture and informatics competency. Conclusion: Based on the results of this study, self-leadership promotion strategies to improve nursing informatics competency are needed.