The purpose of this study was to determine the relationship between professional development practices and teachers’ self-efficacy in Laak South District, Division of Davao de Oro. A predictive correlational research design was utilized to examine the relationship and determine the influence of the study variables. The respondents consisted of 137 public secondary school teachers selected through stratified random sampling. Data were collected using a researcher-adapted survey questionnaire and analyzed using mean and standard deviation, Pearson product–moment correlation, and multiple linear regression analysis. Findings revealed that the level of professional development practices in terms of Learning Action Cell sessions, lesson study, coaching and mentoring, and in-service training was generally high. The results further indicated a significant and moderately high relationship between professional development practices and teachers’ self-efficacy. Among the domains of professional development practices, in-service training, Learning Action Cell sessions, and lesson study emerged as significant predictors of teachers’ self-efficacy, while coaching and mentoring did not show significant predictive influence. The findings highlight the importance of strengthening structured professional development programs and aligning them with teachers’ instructional needs to enhance teaching effectiveness and support continuous professional growth.