Facing the liability of smallness, SMEs face substantial challenges in internally developing solutions to spur the generation of new ideas that challenge existing practices. In this study, we point to co-creation with customers as an external solution to boost radical organizational creativity. Relying on a sample of SMEs in the Northern Netherlands, we examine the impact of co-creation on radical organizational creativity. Following insights from organizational learning theory, we also test the moderating effect of the nature of the organizational structure and the level of organizational creativity support. We find that customer co-creation has a positive impact on SME's radical creativity. Surprisingly, we find that organizational creativity support negatively moderates this relationship. Together these findings enrich our theoretical understanding of the drivers of radical organizational creativity. Moreover, they provide SME managers specific guidelines on how to generate radically new ideas.