Restraint as an intervention in the management of acute mental distress has a long history that predates the existence of psychiatry. However, it remains a source of controversy with an ongoing debate as to its role. This article critically explores what to date has seemingly been only implicit in the debate surrounding the role of restraint: how should the concept of validity be interpreted when applied to restraint as an intervention? The practice of restraint in mental health is critically examined using two post-positivist constructions of validity, the pragmatic and the psychopolitical, by means of a critical examination of the literature. The current literature provides only weak support for the pragmatic validity of restraint as an intervention and no support to date for its psychopolitical validity. Judgements regarding the validity of any intervention that is coercive must include reference to the psychopolitical dimensions of both practice and policy.