There has been a noticeable shift towards sustainability in participatory sport, emphasizing practices such as corporate social responsibility (CSR) initiatives. However, a credible international evaluation tool for assessing the effectiveness of CSR initiatives in sport and recreation services is lacking. This study aimed to adapt and validate a CSR questionnaire for Greek participatory sport, focusing on tennis. The influence of CSR on consumer trust and loyalty was also investigated. A sample of 250 tennis players from a private club in a Greek city participated. A questionnaire assessing CSR in environmental, economic, and social dimensions, was selected after an extensive literature review. Statistical analyses confirmed the questionnaire as a valid and reliable tool for assessing CSR among recreational sports participants. The results indicated that CSR initiatives significantly enhance participants’ trust in the club, which in turn bolsters the club’s credibility. However, CSR initiatives do not directly influence participants’ loyalty; instead, trust mediates the relationship between CSR and loyalty. This underscores the need to strategize on how to convert trust into sustained loyalty. The findings highlight the importance of CSR in building trust, protecting corporate reputation in times of crisis, and supporting long-term sustainability. They provide valuable insights for researchers and sport and recreation managers.

This study examined the effect of a Corporate Social Responsibility (CSR) environmental intervention program on members’ perceptions of economic, social, and environmental responsibility, as well as trust and loyalty, in a tennis club. It further explored whether membership duration influenced these perceptions, with a focus on environmental initiatives. A three-month intervention focusing on environmental initiatives was carried out, involving 250 tennis club members who completed a questionnaire on social, environmental, and economic dimensions before and after the intervention. Data were analyzed using non-parametric tests and repeated measures ANOVA. The findings indicated a significant improvement in perceptions of environmental responsibility, highlighting the effectiveness of targeted CSR environmental intervention. However, perceptions of economic and social responsibility, as well as trust, remained unchanged. Loyalty was negatively affected. Contrary to the literature, membership duration did not significantly influence CSR perceptions. These results emphasized the importance of designing and effectively communicating CSR initiatives that resonate with member priorities. Sports organizations can leverage such environmental intervention programs to improve their image and align with societal values. However, to foster trust and loyalty, CSR efforts across multiple dimensions are necessary. This study contributes to the literature on CSR in participatory sports by demonstrating the measurable impact of environmental interventions and providing a framework for future CSR program development and evaluation in similar settings.