The purpose of this study was to determine the relationship between training needs assessment and the design of professional development plans among public school teachers. A predictive correlational research design was utilized and respondents consisted of 103 public school teachers from the Laak North District, Division of Davao de Oro, selected through proportionate stratified random sampling. Data were analyzed using mean and standard deviation, Pearson product–moment correlation, and multiple linear regression analysis to identify significant relationships and predictors. Findings revealed that the level of training needs assessment and the level of designing professional development plans were generally moderate across all indicators. However, only stakeholders’ involvement and frequency of regularity of implementation emerged as significant positive predictors of professional development plan design, while alignment with RPMS-PPST and systematic data collection were not found to have significant predictive influence. The findings highlight the importance of strengthening participatory processes, ensuring consistent implementation of professional development activities, and enhancing the practical use of evaluation results to improve training design. These outcomes emphasize the need for more structured, data-driven, and collaborative approaches in developing professional development plans to ensure their effectiveness, responsiveness, and sustainability.