The concepts of appropriate and necessary health care are fundamental to the creation of an efficent and equitable healthcare delivery system. To this end the RAND/UCLA appropriateness method (RAM) was developed by RAND and UCLA in the 1980s and has been further refined in North America and Europe. This manual presents step-by-step guidelines for conceptualising, designing and carrying out a study of the appropriateness of medical or surgical procedures for either medical diagnosis or treatment.