This article posits that an economic analysis of the full diversity of organisations providing agricultural advice is needed to explore how societal issues related to environment and occupational health are addressed in the provision of such advice. Our theoretical framework draws on existing research in institutional economics applied to services, in particular to Knowledge Intensive Business Services (KIBS). The methodology is based on a case study, the French seed potato supply chain. The results consider all the KIBS suppliers that deliver advice to farmers in the supply chain. They demonstrate the importance of organisations (linked to upstream and downstream industries) that are often neglected in studies on the pluralism of farm advisory services. Four main types of KIBS are described: client-owned advisory organisations; integrated services where service are developed primarily to accompany a commercial activity; consultancy firms; and parastatals. Each of them design both front-office and back-office service activities, according to their own profitability objectives. The analysis of the performance rationale of these different types of KIBS organisations provides an in-depth understanding of their economic strategies and the reasons why they address - or ignore - the possible adverse effects of their activity on occupational health and the environment. In such a context, public policy seems necessary to frame collective action and integrate environment and human health issues into farm advice. The conditions of efficiency of such interventions are discussed.