In this study, we explored the relationship between teacher autonomy, collaboration with teachers, grit, passion for teaching (i.e. harmonious vs. obsessive), and professional development. In addition, we examined whether grit and passion for teaching play a mediating role between teacher autonomy, teacher collaboration and professional development. A survey was conducted on 312 elementary school teachers working across the country. As a result of confirmatory factor analysis and structural equation model, the data fit the model. Examining the standardized path coefficients of the hypothesized research model, teacher autonomy positively predicted grit and passion for teaching. Teacher collaboration positively predicted passion for teaching. Grit and obsessive passion directly and positively predicted professional development. In addition, the indirect effect in the path of teacher autonomy to professional development via grit was found to be significant, confirming that grit mediates the relationship between teacher autonomy and professional development. This result shows that it is necessary to support teachers' autonomy and create a culture that can promote a cooperative environment, and it is important for teachers to have a sense of purpose and passion for teaching.