The paper aims to examine the influence of a principal's managerial competence on teachers' job satisfaction and work commitment. The study belongs to a quantitative type with a cross-sectional design. The samples are 77 teachers from private junior high schools in Yogyakarta, all of which were selected using a random sampling technique. The data were collected through a questionnaire, which has been tested for validity and reliability. The data were analyzed using PLS-SEM as the samples used were less than a hundred numberwise. The hypothesis testing using PLS-SEM with path coefficient is accepted if the evaluation of the t-statistic is above 1.96 and p-value less than 0.05. The path coefficient revealed several results. First, work commitment significantly influences teachers' job satisfaction. Second, a principal's conceptual competency does not considerably affect the teachers' work commitment and job satisfaction. Third, the principal's interpersonal competency significantly influences teachers' work commitment and job satisfaction. Fourth, a principal's technical competency significantly affects teachers' work commitment and job satisfaction with respectively. Besides, the hypothesis tested simultaneously to the variables and was evaluated using R-square adjusted value path I resulted in 0.762, which means the conceptual competency, interpersonal competency, and technical competency simultaneously influence job satisfaction up to 76.2%, categorized as substantial (strong). Meanwhile, R-square adjusted path II is 0.363, which means that the three competencies simultaneously influence job satisfaction up to 36.3%, categorized as weak. The findings have important implications for those involved in developing teachers' professionalism in that improving a principal's interpersonal and technical competencies will have a positive influence on teachers' job satisfaction and work commitment.