This study aims to examine the influence of organizational culture and work environment. This research was conducted on employees who work at PT Telkom Solo Raya and DIY with a total sample of 125 employees using a random sampling method. Data analysis was performed using Structural Equation Modeling (SEM) analysis with the Smart PLS application. The results of this study indicate that organizational culture has a direct positive effect and the work environment has a positive and significant effect on employee performance. Meanwhile, management knowledge can mediate the influence of organizational culture and work environment on employee performance.