Considering users as innovators has gained considerable support over the past 30 years. Eric von Hippel’s work in this area forms a significant part of the theoretical underpinning and evidence behind this concept. Many further studies have been undertaken to support it. It has contributed to our understanding of innovation management in general and new product development in particular. Even so, Lüthje and Herstatt emphasise that empirical findings are scarce and that the most radical innovations of the last 35 years were not developed by users. Thus, in this paper we critically review the lead-user theory and focus on three specific areas of weakness of the lead-user concept (conceptual, methodological, empirical), and argue that improvement in these areas would considerably strengthen its standing. We conclude that although lead users can contribute to the innovation process, this contribution should not be overstated, and that insufficient attention has been paid to the limitations of this theory.