Non-profit organizations (NPOs) are becoming top players in the business arena and can significantly contribute to socially sustainable development by leading several open innovation (OI) processes. The present study investigated the functioning of an NPO (ELIS, based in Rome, Italy), that acts as an open innovation intermediary in a large consortium of enterprises. By adopting a mixed-method approach, key aspects related to the NPO’s organizational culture, the OI management process within the consortium, as well as leadership skills and values were investigated among 77 employees and 8 managers of the NPO. Results showed that the managers’ approach to OI, teamwork, and market challenges significantly affected the NPO’s ability to produce OI among the consortium members. Moreover, empowering leadership, and a culture of trust and mistake acceptance were highly valued by the NPO in view of an effective OI performance. The study contributes to the current literature by highlighting the conditional factors of the NPO’s capability to create open innovation with enterprises, and push them toward societal change. Implications for OI development have been discussed.