Consultants have taken on an increasingly important role to make improvement schemes come true in a variety of development contexts. Both independent contractors and large firms now undertake multiple roles in development projects, ranging from the role of trainers and advisors to evaluators and researchers. Although research has shown increasing interest in the practices deployed “on the ground” to make development policy real (e.g. Mosse, 2005; Rottenburg, 2009), there are few studies on the explicit role of consultants in this process. This paper explores the role of consultants as important assemblers of international development. Drawing on the concept of assemblage (Deleuze & Guattari, 2013), it is shown that consultants are central for the assembly of development projects as they act as translators and intermediaries between stakeholders. By using translation skills and capacities to make stakeholders aligned to development goals and policies as well as installing the necessary expertise to make development work happen, the practice of consultancy as an act of power is actualized. As consultants have the possibility to render mobile particular “travelling rationalities” (Mosse, 2011), which normalize technical and universal approaches to development, they mobilize a managerial way of imagining development work. Thus, this paper argues that the assembly work conducted by consultants must be critically explored from a power perspective.