The purpose of this study was to determine and analyze the effect of Performance Evaluation on Employee Performance at the Investment Service and One-Stop Integrated Services for Manpower in Dairi Regency. This study employed a quantitative associative causal approach. The sample consisted of all civil servant employees, totaling 39 individuals, selected using purposive sampling. The results showed that Performance Evaluation had a positive and significant effect on Employee Performance. This was indicated by a t-value of 44.054, which was greater than the t-table value of 1.66412, with a significance value of 0.000, which is less than 0.05. The regression coefficient showed that for every 1-unit increase in Performance Evaluation, Employee Performance would increase by 0.957 units, assuming other variables remained constant. Additionally, the determination test results showed an Adjusted R Square value of 0.950 or 95.00%, indicating that Performance Evaluation had a very high impact on Employee Performance, while the remaining 5.00% was influenced by other factors not examined in this study. Therefore, it can be concluded that, partially, Performance Evaluation had a positive and significant effect on Employee Performance at the Investment Service and One-Stop Integrated Services for Manpower in Dairi Regency. This finding identifies that improvements in Performance Evaluation can contribute to enhancing Employee Performance.