In January 1985, the author of this study was employed as a scientific staff member at CBO, the Dutch National Organisation for Quality Assurance in Hospitals. His main job was to support peer review committees of medical specialists in hospitals. The task proved to be challenging and was broadened to an active involvement in the consensus development programme run by CBO'S scientific council. Both peer review and guideline development through consensus conferences turned out to be far more complex activities than might be expected at first sight. Hence over the years the ambition emerged to study these phenomena more thoroughly. From the beginning it was clear that peer review and guideline development are only two of the various systematic activities the medical profession has developed to manage the quality of specialist care. This study is rooted in the curiosity to understand these activities and in its essence the study tries to provide an answer to two questions: • What is quality management of medical specialist care? • How does it develop?