The complexity of studies concerning the development of inter-organisational information systems (IOIS) over large timescales poses severe challenges on existing models and theoretical frameworks. Such ‘evolutionary’ research requires multiple perspectives on the phenomenon in order to account for changes as well as persistent elements of the IOIS. In this paper the theoretical concept of ‘structural coupling’ derived from autopoietic theory is proposed as a means to conceptualise the required alignment of independent organisations that venture into an IOIS. The need for a new concept is motivated against the backdrop of a case study covering the evolution of an electronic ordering system over almost three decades. Subsequently, the case study is used to illustrate the applicability of the concept to the empirical data. The paper finds that conceiving IOIS as structurally coupled systems offers a new and promising venue to study these systems on large timescales.