The Indonesian construction industry frequently experiences delays and cost overruns due to ineffective project management. This study aims to explore the relationship between project manager knowledge, specifically in the areas of leadership, communication, and technical skills, and its impact on project success. Using Partial Least Squares Structural Equation Modeling (PLS-SEM) and Necessary Condition Analysis (NCA), data from 120 project managers were analysed. Findings reveal that both tacit knowledge and explicit knowledge significantly influence success, with tacit knowledge having a stronger total. Additionally, the NCA results indicate that leadership and technical skills are necessary conditions for achieving project success. Specifically, a minimum of 13.33% knowledge in leadership and 30.83% knowledge in technical skills are required to achieve 80% of project success. The study emphasizes the vital role of knowledge in improving project outcomes. © 2025 by the authors; licensee Growing Science, Canada.