Background: Performance-Based Financing (PBF) has been advanced as a solution to contribute to improving the performance of health systems in developing countries. This is the case in Benin. This study aims to analyse how two PBF approaches, piloted in Benin, behave during implementation and what effects they produce, through investigating how local stakeholders perceive the introduction of PBF, how they adapt the different approaches during implementation, and the behavioural interactions induced by PBF.Methods: The research rests on a socio-anthropological approach and qualitative methods. The design is a case study in two health districts selected on purpose. The selection of health facilities was also done on purpose, until we reached saturation of information. Information was collected through observation and semi-directive interviews supported by an interview guide. Data was analysed through contents and discourse analysis.Results: The Ministry of Health (MoH) strongly supports PBF, but it is not well integrated with other ongoing reforms and processes. Field actors welcome PBF but still do not have a sense of ownership about it. The two PBF approaches differ notably as for the organs in charge of verification. Performance premiums are granted according to a limited number of quantitative indicators plus an extensive qualitative checklist. PBF matrices and verification missions come in addition to routine monitoring. Local stakeholders accommodate theoretical approaches. Globally, staff is satisfied with PBF and welcomes additional supervision and training. Health providers reckon that PBF forces them to depart from routine, to be more professional and to respect national norms. A major issue is the perceived unfairness in premium distribution. Even if health staff often refer to financial premiums, actually the latter are probably too weak-and ‘blurred’-to have a lasting inciting effect. It rather seems that PBF motivates health workers through other elements of its ‘package’, especially formative supervisions.Conclusion: If the global picture is quite positive, several issues could jeopardise the success of PBF. It appears crucial to reduce the perceived unfairness in the system, notably through enhancing all facilities’ capacities to ensure they are in line with national norms, as well as to ensure financial and institutional sustainability of the system.