As health care costs continue to rise in Canada, there is a need to evaluate the resources required for diagnosing and treating the major diseases having an impact on Canadian. In 1993, breast cancer was the most predominant female cancer in Canada, both in terms of incidence and mortality. It would be useful to identify the direct health care costs associated with this disease and to create an analytical framework within which diagnostic and therapeutic options can be assessed. This paper provides a description of the approach to be taken in developing a realistic conceptual model of the management of all stages of breast cancer, including diagnostic and treatment approaches, survival outcomes and costs. It includes an outline of our research objectives, a description of the kind of information required, a section on the methodology and sources to be used, and a brief explanation of the analytical framework into which it will be incorporated and used.