This paper explores how Supportive Leadership influences Communicative, Collaborative and Performance Management practices and how these three practices, in turn, relate to the Job Satisfaction of public servants within the European Court of Auditors (ECA) context. The empirical exploration statistically tests a theoretical model about the direct and indirect effect of Supportive Leadership on employees’ Job Satisfaction by considering the responses to a survey administered to the ECA staff. The findings of our study show that Supportive Leadership has a direct positive effect on the Job Satisfaction of the ECA employees. The mediation analyses reveal that Communication and Collaborative practices provide a better explanation in the relationship between Supportive Leadership and Job Satisfaction. The analyses show that Supportive Leadership has a significant positive relationship with the effective communication and collaborative practices and these in turn have a significant positive relation with Job Satisfaction of the ECA employees. In the case of Performance Management Practices, instead, we find that, while the Supportive Leadership has a significant positive relation with Performance Management Practices, these practices have no significant relationship with Job Satisfaction. This study does not only address the theoretical void in the field, but also provides an empirical contribution by describing how a professional European audit institution is managing its human resources and the means of doing it.