Résumé : Introduction: Performance-based financing (PBF) is promoted as a way to improve health workers’ performance. However, despite a growing interest in the issue of motivation and the use of several motivational theories to appraise it, little is still known about PBF internal mechanisms leading to behavioural change, even less on their sustainability. The recent termination of donor-funded PBF programmes in Benin represents a unique opportunity to analyse which motivational mechanisms are sustained when incentives cease.Aim: This study aims to refine the understanding of PBF by using the I-change model1 and to explore how PBF affects health workers behavioural change in Benin during implementation and after termination. Methods: Our study rests on a qualitative design. We conducted semi-structured interviews with healthcare providers and managers from health centres (N=6) and hospitals (N=2) in two health districts supported by different donors), first during PBF implementation in 2017 and secondly, with some of the stakeholders previously interviewed (N=40), 6 and 9 months after the programmes stopped. Interviews were analysed thematically. Results: PBF produced positive effects on some health workers’ behaviours, like interpersonal communication and reporting, that are sustained after PBF termination. During implementation, the prospect of extra gain contributed to the motivation of health workers to adopt these behaviours, however that effect was reduced due to low level and perceived unfair distribution of financial incentives, and reversed with their cessation. Beyond financial incentives, other mechanisms also play an important role in health workers behaviours adoption, which persisted after PBF termination, notably awareness of inner duty, social pressure, and demonstration of the usefulness of some practices. However, some systemic constraints, design and implementation issues, and the absence of an exit strategy reduced their motivational effect. Conclusion: Our behavioural change analysis using the I-change model helps refine the understanding of PBF and sheds light on its effects on health workers’ behaviours that go beyond the effects of financial incentives, but can be reduced by systemic constraints, design, implementation and exit strategy issues. Reference:1. De Vries H., Dijkstra M., Kuhlman P. Self-efficacy: the third factor besides attitude and subjective norm as a predictor of behavioral intentions. Health Education Research 1988; 3; 273–282.