The aim of the study reported here was to evaluate current initiatives in GP-hospital integration and highlight areas where further research, development and evaluation are required. Seven pre-existing GP-hospital programs were selected and given supplementary funding to allow for more effective evaluation. These local evaluations were then incorporated into a national program on GP-hospital collaboration. We found that the seven projects made substantial progress towards their goals, and in the process highlighted important aspects of successful collaboration. The collective evaluation of DHIP identified expected benefits of collaboration for patients (improved access to services, reduced anxiety, and fewer post discharge complications), for GPs (increased involvement in acute care and in hospital decision making), and for service organisations (stronger working relationships, increased capacity, and greater efficiency). Barriers to service integration were also identified, including the different cultures of Divisions and hospitals, their lack of internal coherence and the Commonwealth-state divide. The evaluation showed that much has been achieved in building the relationships and the capacity needed for GP-hospital collaboration, and that effective models exist. The current challenge is to extend successful models across health areas and make effective collaboration part of the normal system of care. Substantial progress towards integrated care relies on a shift from a focus on systems within general practice or hospital environments to a patient centred approach. This will require general practice, hospitals, community services and consumer organisations to form long term partnerships and move beyond their currently disjointed view of acute and community care. The development of practical indicators for integrated care will support the process and facilitate shared learning across Commonwealth and state divides.