Nanotechnologies are known as emerging technologies. In contrast to this there are already products on the market that claim to incorporate these technologies. This has contributed to the growing interest in the regulation of this field. In this paper, we first introduce the question of regulation in nanotechnologies, then describe the standardisation process and ISO more specifically. This introduction is followed by the main point of the article: we show the specific role that the ISO TC 229 plays in the beginning of the shaping of a collective vision for nanotechnologies. We point to the organisation and re-organisation of TC 229 that allows actors to build a collective representation of the evolving field and build legitimacy at the global level. We argue that beyond the production of standards, this aspect is central in an emerging field that will impact regulators as they design new rules.