Collective entrepreneurship is conceived as various individuals' capacity to collaborate, innovate and create within organisations. Despite some studies relating the role of leadership and collective entrepreneurship, there is a research gap regarding the health care sector. Consequently, the objective of this study is to understand the role of leadership in promoting collective entrepreneurship within health organisations. In order to achieve this aim, a quantitative cross-sectional research approach was adopted, based on a questionnaire administered to a representative sample of nurses in a Local Health Unit in Portugal. Here, the focus is on transformational and transactional leadership styles, as they are quite popular and can be particularly promising in promoting collective entrepreneurship. The outcomes reveal that leadership has a dominant role in the context of health organisations, since a strong relationship was found between transformational leadership and nurses' collective entrepreneurial capacity. This positive relationship can be explained because transformational leaders and their subordinates show common interests in objectives, which generates higher levels of motivation and service provision. The research conducted represents an innovation in academic terms as it relates leadership and collective entrepreneurship in a very little explored context. In practical terms, the results allow the conclusion that transformational leadership is highly relevant when it comes to promoting collective entrepreneurship. Hence, health organisations must be made aware of this type of leadership, in order to increase the collective entrepreneurial capacity of their collaborators.