Veblen’s concept of conspicuous consumption, although widely known and commonly invoked, has rarely been examined critically, while the associated ‘theory’ has never been tested. It is suggested that the reason for this lies in the difficulty of determining the criterion that defines the phenomenon, a difficulty that derives from Veblen’s failure to integrate two contrasting conceptual formulations. These are, first, an interpretive or subjective version that conceives of conspicuous consumption as action marked by the presence of certain intentions, purposes, or motives, and second, a functionalist formulation in which conspicuous consumption is viewed as a form of behaviour characterized by particular end results or outcomes. Consideration of each of these strands reveals major difficulties that prevent the construction of an operational definition of conspicuous consumption and hence the extraction of a workable theory from Veblen’s discussion.