Collaborative inter-professional practice (IPP) is hailed increasingly by policy-makers and a growing number of practitioners as "the" new form of professional practice for those working within and across services for children and young people. Based on desk research, and drawing upon an increasingly invasive use of the term "collaborative" at macro as well as micro-levels of the state, this paper interrogates the discursive and organisational forms upon which this "new" advocacy rests and permeates the fields of Education, Health, Social Care, and Social Work, including standards agendas. Definitional complexity is compounded, it is argued, by relative paucity in evidence to demonstrate its benefit to and purposes for users/clients/students and professionals. Summarising evidence from case examples, conclusions draw attention to the need for more rigorous research not only about the benefits and disbenefits of inter-professional education (IPE) and collaborative IPP but also about the purported causal links between them. (Contains 1 note.)