There has been a noticeable gap in scholarly research concerning managers' ambidexterity in entrepreneurial firms, particularly in startups. This quantitative study examines the degree of influence of transversal competencies related to ambidexterity in startup managers of Chilean firms. Findings indicate that CEO perseverance, enterprising, business orchestration, and networking positively affect managers' ability to balance exploration and exploitation activities. The study also suggests that the firm's age does not moderate the relationship between competencies and ambidexterity except for business orchestration. In addition, the article<acute accent>s major contribution is to connect transversal competencies in startup CEOs and the micro-foundations theory of ambidexterity, highlighting the importance of individual cognitive predispositions since resilience and motivational dimensions. Indeed, the study identifies perseverance and enterprising as competencies with a higher impact in these entrepreneurial high-tech firms.