The study aims to explore how startup leaders communicate their vision and use strategic ambiguity in uncertain and dynamic environments, as well as how employees understand the vision. Transitioning from being an entrepreneur to being a leader is challenging. Effective leadership communication in startups is crucial due to its impact on survival rates of businesses and the more direct interaction with employees, compared to established organizations. Previous studies found that effective vision communication motivates followers, thus contributes to the startup’s growth. However, how startup leaders communicate and how members perceive vision in constant changes remain underexplored. The study addresses this gap by investigating how startup leaders use vision communication and its impact on employees' perception and organizational performance as well as how startup leaders use ambiguity as a strategy in uncertain situations. The data was collected through multiple qualitative methods, including observations, case studies, and semi-structured interviews, and analyzed by constant comparison method. The study found that early startup entrepreneurs often communicate a flexible vision that evolves as they bring on new clients and the organization develops. Employees interpret the vision by executing their tasks that are aligned with the vision. Strategic ambiguity is rare in smaller startups due to frequent interactions and task-oriented communication pattern. Theoretical and practical implications of the findings are discussed.