ABSTRACT Research question: Understanding corporate social responsibility (CSR) implementation requires identifying factors that contribute to the ability of a sport organisation to develop CSR. This paper examines the complex combination of organisational factors associated with CSR implementation in a sport federation (SF) setting. Thus, this study identifies organisational factors of professionalisation for CSR implementation and different configurations associated with CSR implementation. Research methods: The study adopted a comparative approach combining a survey, interviews, and organisational documents in a sample of 19 Belgian SFs. A crisp-set Qualitative Comparative Analysis (csQCA) was carried out to identify the combination of organisational factors associated with CSR implementation. Results and Findings: This study identifies four configurations associated with high CSR implementation and three configurations with low CSR implementation. Innovation capacity is a necessary organisational factor for CSR implementation that should be combined with financial autonomy, knowledge and human resources. The study reveals that organisational size is not a key condition associated with CSR implementation. The latter does not necessarily require a significant number of professional staff as long as the organisation is innovative and financially autonomous. Implications: This study contributes to the emergent research in the sport management literature and CSR literature on factors shaping CSR implementation by highlighting that it requires a combination of key organisational factors. The multiple configurations that emerged reveal the complex nature of CSR implementation, and reinforce the view that there is no ‘one size fits all’ solution to implement CSR.