One aspect that has received little attention in COTS selection is what we call conceptual fit, which we evaluate in terms of the existing misfits. We define the notion of conceptual misfit and we present an approach that determines the conceptual misfits between the user requirements and a set of candidate systems. The approach consists in defining a superschema, the mapping of the conceptual schemas of the candidate systems and of the user requirements to that superschema, and the automatic computation of the existing conceptual misfits. We believe that conceptual fit could be taken into account by almost all existing COTS selection methods. Keywords. Conceptual Fit, COTS selection, Conceptual Modeling