The Norwegian Government emphasizes intersectoral collaboration to achieve health goals such as reducing social health differences. However, research shows that achieving fruitful collaboration between different organizations and the public sector is challenging. The sports sector is one potential partner for such collaboration. Although the Government calls for intersectoral collaboration that includes the sports sector, there are few concrete guidelines for how this may be implemented in practice. Guided by The Bergen Model of Collaborative Functioning, the purpose of this study was to explore factors that promote or inhibit collaboration in an intersectoral project involving the sports sector, NGOs, and public sector. The current project aimed to work towards creating health promoting activities aimed at vulnerable youths. Methods: A qualitative case study of the Sports Project with interviews of eleven collaborative partners. Results: Factors promoting collaboration amongst the different partners were having a common mission, an appreciation of the partners’ complementary skills and knowledge, and a consistent user perspective. Conclusions: By orienting the collaboration towards the users’ needs, the partners have succeeded in creating tailored health-promoting activities for vulnerable youths. However, a challenge remains in transforming the collaborative project into a sustainable structure.