The government's health policy now demands effective collaboration between organizations, between commissioners and providers of care and between health and local authorities, the voluntary sector and the public. Making collaboration work at operational and strategic levels is a significant management challenge. This paper draws on experience and observation of two forms of strategic collaborative venture that have been established with the ultimate purpose of improving the public's health. The first concerned itself with mechanisms for commissioning health and social care services on a locality basis, while the other venture was concerned with the promotion of physical activity across a health authority district. Using a framework which identifies the forms of value attributable to collaborative working, the analysis evaluates the processes of development of the two initiatives and identifies some key lessons for developing sustainable collaborative ventures. The framework used is proposed as being appropriate for the formative evaluation of future collaborative initiatives.