The purpose of this study is to see the extent to which achievement orientation competencies can be improved by learning from others and learning on the job with mentoring intervention methods. This study uses a quasi-experimental method with the one group prettest-posttest design with Friedman test as an analysis technique. The subjects of this study are employees who have supervisory positions to managers who have competency gaps. This research involved 20 respondents. Achievement orientation competency is measured using a scale based on the subdimention of PT.X Competency Directory. Measurements were made before and after mentoring. The results showed that there was a very significant difference in the level of achievement orientation competence among several treatments with a significance of 0,000 (P <0.01). Mentoring also has a large effect size measured by using a cohen's d effect size of 0.99, meaning that mentoring has a large influence on increasing the achievement orientation competency.