This chapter argues that planning theory's productive engagement with Foucault's toolbox can be usefully extended by re-focusing analytical attention on the production of the disciplinary 'apparatus' of planning – the various institutions, discourses and practices through which the field called 'planning' and its truths are constructed at different times and in different places. It discusses that Foucault's largely historical thinking might be usefully supplemented by attentiveness to the lived experiences of practice and particularly the forms of 'cultural work' through which planning's disciplinary apparatus is actively reshaped. Work influenced by Foucault's thinking has generated powerful contributions to planning theory, notably in unsettling the claims of the planning project to be a progressive force for social change. Genealogical rather than archaeological analyses have tended to prevail when Foucauldian tools have been used in planning. Such studies have shown the potential of Foucauldian approaches for exploring the construction of planning as a discursive formation or apparatus.