Purpose – The aim of the article is to identify the desired leadership competencies and behaviors that affect business success, with particular emphasis on innovative start-up organizations. Research method – The publication was created based on the analysis of the existing data. In addition, the quantitative research results (2020–2021) in Lublin Voivodeship were analyzed for the doctoral thesis. The focus was on the competencies and behaviors of start-up leaders/founders that influence success. A survey questionnaire was used in the study. Results – The most crucial task of a leader is to focus on employees, inspire them to carry out tasks according to the organization’s interests, and skillfully use their distinguishing features and competencies. Success in a start-up is possible when its leader/founder focuses on the decision-making process and relational capital and is convinced of the success of the assumed goals. Originality /value /implications /recommendations – The completed research are essential from the perspective of the further search for leadership competencies and behaviors that affect success in various types of organizations, with particular emphasis on modern business models. The use of appropriate competencies and behaviors by the leader/founder of a start-up guarantees: the transition to the next stage of the start-up’s development, increase in its value, increase in the strength of internal relations, implementation of the assumed social goals and deepening cooperation with external stakeholders.