Based on an analysis of an international professional network that advocates for public participation over the world (IAP2), this article aims to study the issues, modalities, conditions, and limits of the international standardization of participatory tools and practices. At first sight, the work of this association to standardize, codify, and promote the values and tools of public participation for use all over the world seems to illustrate the standardization and the internationalization of participatory engineering. But after analysis, IAP2’s work reveals the weakness of the process. On one hand, the logic of spreading and the logic of merchandizing these standards are in tension, and on the other hand, the community of public-participation professionals is still fragmented, competitive, and weakly internationalized.