This paper makes the claim that establishing successful multi-professional working in Children's Centres can be viewed as the art of the possible when the work focuses on children's needs rather than on the availability and expertise of the multi-professional team. This requires a model for working that enables loose flexible arrangements of professional networks in order to collaborate on specific cases, thereby starting with the needs of the child. Exploring through interviews the working practices as perceived by a number of different professionals working in two Children Centres in London, the data identifies difficulties and contradictions in joint professional work.