This paper focuses on the identification of interorganisational drivers for biomass valorisation that create relational rents. Given the growing interest in the valorisation of biowastes it is posited that entrepreneurial firms develop interorganisational relationships to generate competitive advantages. The literature study of transaction cost theory, resource-based theory, and network theory brought about four plausible drivers for innovative business development in biomass valorisation. The newness of research on biomass valorisation, scarcity of good data and confidentiality issues made explorative research necessary, and therefore the case study method was applied on six focal firms in the Netherlands. The results confirm the relevancy of three out of the four suggested drivers for biomass valorisation that create relational rents, namely: complementary resources, partner alignment and relationship governance.