Working in a cooperative manner with other disciplines or agencies is often cited as an essential element of social work with adults who self-neglect (Barnett, 2018; Braye et al, 2011). Cooperative working is now a legal requirement for agencies involved in adult social care in England. However, little is known about how social workers engage cooperatively with other disciplines in practice. This study sets out to explore this issue, employing the ‘Logic of Appropriateness’ perspective (March and Olsen, 2013) to theorise the ways in which social workers talked about working with other disciplines in self-neglect casework. The article presents a qualitative study, which was undertaken through semi-structured interviews with 11 social workers in an urban, adult social care team in an English local authority. Thematic analysis was used to draw out four key logics used by the social workers — leadership, joint-working, conflict, and proxy — but also highlighted the ways in which social workers moved between different logics when talking about cooperative work and working with adults who self-neglect. The results highlight the complex dynamics of cooperation, and suggest that these dynamics need to be understood in assessing the implementation of integrated policies for social care in this area.