Purpose To understand the context surrounding the sustainable supplier management (SSM) process (i.e. selection, development and evaluation), this paper aims to explore institutional logics existing in the Ecuadorian cocoa supply chain (SC). By considering local characteristics and sustainability practices, this study illustrates how competing logic influences SSM. Design/methodology/approach This paper uses a multiple-case study method for which the authors interviewed different cocoa SC members in Ecuador and used a ground-up approach to analyse the data and reveal singularities influencing sustainability management. Findings The analysis uncovered two main logics operating within the Ecuadorian cocoa SC SSM process: a commercial logic (e.g. potential for market access, product traceability) and a sustainability logic (e.g. local development and traditions/cultural issues). These logics address market demand requirements; however, some local producers’ needs that impact SSM remains unexplored such as the existence of a regional ancestral culture that poses sustainability as a dominant logic with meaning beyond the triple bottom line. While the two logics have influenced supplier sustainability performance, this paper finds that, of the three SSM sub-processes (selection, development and evaluation), supplier development was the most relevant sub-process receiving attention from SC managers in the studied context. Practical implications By understanding the differences in logic and needs, SC managers can better develop strategies for SSM. Originality/value The study highlighted in this paper investigated the underexplored topic of the effects that competing logic may have on SSM. This paper focusses on the supplier’s point of view regarding sustainability requirements, addressing a consistent research gap in the literature.