<p>Environmental degradation in agriculture remains a pressing issue, with key ecological indicators continuing to decline despite the longstanding policy objectives and public support for curbing environmental degradation. Biodiversity, particularly for natural pest control, is crucial for sustainable farming. The limited success of current policies to stimulate adoption of such practices can partly be attributed to a lack of attention to policy acceptability amongst farmers during ex-ante evaluations, leading to resistance or hesitance at the implementation stage. This paper tests the acceptability of different policy instrument types (categorized under the RESET framework) aimed at increasing the adoption of biodiversity-friendly practices through a survey among 99 outdoor vegetable farmers in Flanders. We explore variation in acceptability across different farmer profiles through a factor and cluster analysis. Policy instruments focused on education, advice, and knowledge exchange, including training courses, subsidised farm advice, demonstration farms, information sessions, and smart decision-support systems, received consistently high acceptability scores. In contrast, pull-based measures such as hybrid payments, voluntary labels, biodiversity monitoring tools, and collective efforts elicited mixed responses, while regulatory and penalising instruments (e.g. mandatory non-productive areas, pesticide taxes, bans) were generally less acceptable. Cluster analysis identified three farmer profiles; Sceptics, Moderates, and Enthusiasts; with Enthusiasts, typically younger, more educated and organic-oriented, showing high acceptability across most instruments. Based on our findings, we provide recommendations for policy design and for more targeted implementation strategies. The paper concludes by advocating for the systematic inclusion of acceptability assessments in the ex-ante design of agri-environmental policies.</p>