This study aims to determine the effect of internal motivation, preventive discipline and work environment on the performance of employees of the drinking water company in Purbalingga Regency. This research uses quantitative methods. The population in this study were all permanent employees of the Purbalingga Regency PDAM. The sampling technique uses simple saturation / census. The sample in this study was 103 respondents. The analytical tool used in this study is validity test, reliability test, classic assumption test, multiple regression analysis, t test and F test. The results of the study show that internal motivation variables, preventive discipline and work environment have a simultaneous effect on employee performance. The results of the partial test showed that internal motivation and work environment had a significant effect on employee performance, while preventive discipline did not significantly influence employee performance.