In the field of Urban Studies, there is an evident need to rethink the scope of investigative methods due to the multiple transformations of contemporary urban life. The objective of this article is to expose in a dialogic way the notion of scale from the Critical Urban Theory and Urban Assemblage, especially linked to the Actor-Network Theory. The text highlights possible implications when adopting multi- or trans-scalar theoretical-methodological approaches in Urban Studies. In this sense, we present the main divergences, possible convergences and complementarities between them.