This paper aims to advance the process dimension of inter-organisational adaptation that takes places in supply chain relationships, building upon learning literature. Therefore, it summarizes and disentangles the different debates on inter-organisational adaptation and learning in the literature and establishes the theoretical linkage between both concepts. Two dyadic case studies show that the learning processes that underlie inter-organisational adaptations may be comprehensively classified based upon the direction of learning, resulting in "learning from" versus "learning with", and based upon the span of learning, resulting in "incidental learning" versus "incremental learning". The experiential nature of learning provides an explanation for the reinforcing character of inter-organisational adaptation, which is an alternative to the explanations presented in literature on supply chain relationships. © 2010 Elsevier Ltd.