Currently the application of TQM in PT. Yodya Karya (Persero) still has a few obstacles, among others, there are still employees who do not understand what is meant by TQM. This situation is unfortunate because some literature suggests that successful implementation of the application of TQM bring a good impact on improving the quality and increase the commitment of employees could ultimately trigger employees to improve performance. On the other hand, one important factor for the successful implementation of TQM is leadership. Thereby, based on current conditions faced by PT. Yodya Karya (Persero) and literature that says that there is a relationship between transformational leadership, implementation of TQM, organizational commitment, and employee performanceThe respondents of consisted of 117 employees of PT. Yodya Karya (Persero) Region I in Semarang. Data analysis tool used is SEM (Structural Equation Modeling), which is operated with the AMOS program 19.0.This study concluded: There is a positive and significant effect of transformational leadership and application of TQM on organizational commitment. There is a positive and significant influence between transformational leadership and application of TQM on employee performance. There is a positive and significant influence between organizational commitment to employee performance.