Background: The 4-year (2007-2011) Revitalizing Health for All international research program (http://www. globalhealthequity.ca/projects/proj_revitalizing/index.shtml) supported 20 research teams located in 15 lowand middle-income countries to explore the strengths and weaknesses of comprehensive primary health care (CPHC) initiatives at their local or national levels. Teams were organized in a triad comprised of a senior researcher, a new researcher, and a 'research user' from government, health services, or other organizations with the authority or capacity to apply the research findings. Multiple regional and global team capacityenhancement meetings were organized to refine methods and to discuss and assess cross-case findings. Objective: Most research projects used mixed methods, incorporating analyses of qualitative data (interviews and focus groups), secondary data, and key policy and program documents. Some incorporated historical case study analyses, and a few undertook new surveys. The synthesis of findings in this report was derived through qualitative analysis of final project reports undertaken by three different reviewers. Results: Evidence of comprehensiveness (defined in this research program as efforts to improve equity in access, community empowerment and participation, social and environmental health determinants, and intersectoral action) was found in many of the cases. Conclusions: Despite the important contextual differences amongst the different country studies, the similarity of many of their findings, often generated using mixed methods, attests to certain transferable health systems characteristics to create and sustain CPHC practices. These include: 1. Well-trained and supported community health workers (CHWs) able to work effectively with marginalized communities 2. Effective mechanisms for community participation, both informal (through participation in projects and programs, and meaningful consultation) and formal (though program management structures) 3. Co-partnership models in program and policy development (in which financial and knowledge supports from governments or institutions are provided to communities, which retain decision-making powers in program design and implementation) 4. Support for community advocacy and engagement in health and social systems decision making These characteristics, in turn, require a political context that supports state responsibilities for redistributive health and social protection measures.