This paper describes a typical procedure for the development of credentialing examinations. Specifically, the paper provides the developmental history of the Certification Examination for Gastroenterology Nurses and Associates. In the course of the paper, a four-step approach to examination development is outlined. The steps include role delineation, item writing, examination construction and passing score determination. All phases of the examination development process are viewed in the light of their contribution to the public protection responsibility of the Certifying Board of Gastroenterology Nurses and Associates.