Organisational Development (OD), with its focus on partnership working and distributed leadership, is increasingly advocated as an effective approach to driving change. Our evaluation of the impact of OD on delivery of integrated care in three London boroughs sheds light on how OD is being understood and implemented within health services, and what impact it is having on delivery of care. The findings presented here are based on a qualitative and participatory evaluation. We looked at how health and social care professionals communicated and coordinated delivery of care and evaluated the impact of current OD activities on the ground to evidence whether and to which degree they are enabling frontline staff to change their working routines towards greater coordination. Our findings highlight the limited reach and scope of a top-down approach to OD based on ad hoc coaching and staff engagement events, often delivered by external consultancies, and mostly focused at the senior management level. This approach fell short of enabling the creation of sustainable, integrated and collaborative organisations. Instead, some of the professionals that participated in our study tried to develop spaces that facilitated ongoing dialogue and mutual support among professionals on the ground. Initiatives of bottom-up OD such as those described in this paper have greater potential to change working routines as they enable staff to move towards more collaborative and coordinated work. These findings contribute to the literature on OD in public services and highlight the benefits of a context-sensitive, pragmatic, and long-term approach to OD to help create sustainable collaborative organisations