Purpose: This study aimed to analyze the factors influencing self-leadership among public health nurses as they implement health promotion projects in public health centers and primary healthcare posts. Methods: The study sampled 120 public health nurses from 22 public health centers and their associated primary healthcare posts in J province. Data were collected from October 11 through October 25, 2022. Results: Employment at a primary healthcare post instead of a public health center (β=.23, p=.012), was significantly associated with self-leadership in model 1 (adjusted R2=.17, F=4.56, p<.001). Furthermore, communicative competence (β=.48, p<.001) and nursing professionalism (β=.26, p=.001) were significantly associated with self-leadership in model 2 (adjusted R2=.51, F=14.77, p<.001). Conclusion: Open and self-directed work environments, along with opportunities for education and training, are necessary to enhance communicative competence and nursing professionalism. These improvements may, in turn, strengthen self-leadership among nurses, facilitating the implementation of health promotion projects within public health institutions.