The construction industry has a wealth of information and knowledge that grows naturally through construction projects. The construction firm is required to be able to manage knowledge in order to achieve company goals and sustainability. The success of a construction company can be represented by its ability to maintain the quality of construction products, achieved through an effective quality management process. The culture prevailing among company employees is an important factor that contributes to the implementation of quality management practices. The objective of this study is to analyze the influence of knowledge management and organizational culture on quality management in construction firms. The scope of this research encompasses large-size construction firms located in East Java, totaling 26 firms with a sample size of 69 respondents. Analysis of the conceptual model uses the Structural Equation Modeling—Partial Least Square (SEM-PLS) method with the SmartPLS v.4 software. The results indicate that knowledge management has a significant effect on quality management, with a T-Statistic value of 2.923 and P values of 0.003. Furthermore, organizational culture also has a significant effect on quality management, with a T-statistic value of 6.178 and P values of 0.000. This research contributes to enriching the study of knowledge management, organizational culture, and quality management improvement in the construction sector.