Introduction To stimulate physical activity (PA) and guide primary care patients towards local PA facilities, Care Sport Connectors (CSC) (in Dutch Buurtsportcoach), to whom a broker role has been ascribed, were introduced in 2012. This function is new, and to our knowledge no study has yet explored a broker role and its impact on improving intersectoral collaboration between both sectors. The aim of this thesis was to explore CSCs’ role and impact in connecting the primary care and the PA sector. Method This thesis employed a multiple case study design in which 15 CSCs from nine municipalities spread over the Netherlands were followed in their work from 2014 to the end of 2016. Different data collection methods were used (literature review, interviews, focus groups, document analysis, and questionnaires), and perspectives of different stakeholders (policymakers, professionals, CSCs) on different levels (policy and community) were taken into account (Chapter 2). Results The connection between the primary care and the PA sector: a chain approach The connection between both sectors can be characterised as a chain in which CSCs guide the target group towards PA facilities after referral by primary care professionals or their own recruitment. In this connection CSCs fulfilled three roles - broker, referral, and organiser – which did not change over time (Chapter 4 and 5). Barriers at system and sector level hinder the established connection Barriers related to the primary care (lack of time, money and knowledge) and the PA sector (lack of suitable PA activities and adequate instructors) are currently hindering the connection between both sectors (Chapter 4 and 6). Barriers related to the collaboration between both sectors, like cultural differences and different interests as identified in our literature review (Chapter 3) were not identified. The importance of an integral approach for CSCs and the connection between both sectors An integral approach to structural embed CSCs (Chapter 7) seemed to influence CSCs’ work and subsequently their impact. CSCs working in municipalities who structurally embedded CSCs only at the PA sector, connected both sectors mostly by jointly organising activities. CSCs working in municipalities who adopted an integral approach connected both sectors by a variety of activities targeting different audiences, and primary care professionals fulfilled mostly a role in the referral of their patients. The structural imbedding of the CSC according an integral approach seems the most promising in reaching the desired outcomes (Chapter 8). Conclusion CSC’ role is promising for establishing a connection between the primary care and the PA sector. However, to make a success of the connection changes are needed at system and sector level. Further research should focus on CSCs’ impact on stimulating PA among primary care patients, and the development of CSC’ role and the connection between both sectors over time.