This research is done to find out: (1) the condition of employee work discipline and employee performance in PT.Riodi Jaya Medan city branch, (2) the effect of employee work discipline on employee performance in PT.Riodi Jaya Medan city branch. This research is done with quantitative approach. The subject in this study was the employees who are working at PT. Riodi Jaya Medan city branch. The population in this research is 47 people. The sample technique used in this research is census sampling. Data are gathered with questionnaires that have passed the validity and reliability test. This research is with the significant level of 5% in mind and the results are: (1) correlation of determination is 0.566, (2) simple linear regression is 0.927 + 0.488X. The conclusion of this research is the condition of work discipline is good and the condition of employee performance is enough. This research can be used to strengthen previous and future research that there is an effect between work discipline and employee performance. The recommendation in this research is to further improve work discipline by creating wages cutting disciplinary rules and to further improve employee performance by limiting chance to ask for permission and by doing briefing every morning. Thus, hypothesis alternative (Ha) is accepted that employee work discipline has significant influence on employee performance in PT.Riodi Jaya Medan city branch.