As the multiplicity of uses to which nanomaterials may be put can make it difficult to locate appropriate regulatory regimes in Europe, it is chemicals policy that has the greatest potential (realisable or otherwise) for the substantive governance of nanosubstances. The Regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals, commonly known as REACH, is overwhelmingly likely to take up much of the regulatory burden. This paper explores the capacity of REACH to accommodate nanomaterials within its regulatory compass. The paper comprises three sections plus a conclusion. The first covers the absence of an explicit regulatory framework for nanosubstances within the EU, and the second provides an overview of regulation under REACH. The third section constitutes the vast majority of the paper by analysing the application of REACH to nanosubstances. This final section concludes by exploring possibilities for the substantive regulation of nanosubstances within REACH. The paper argues that asking REACH to regulate nanosubstances (when the challenges faced by the Regulation in regulating bulk substances are massive) is perhaps expecting too much.