Background: Healthcare systems are widely interested in developing clinical practice guidelines (CPG) in order to improve quality of care, support organizational purposes and reduce variation in clinical decisions. Priority setting is a main step in a successful CPG development process. Some methods had been described for selection and scoring topics for CPG, although no systematic reviews deal with the methodology for priority setting and selection of participants in prioritization. Objectives: This study will review the strategies and methods published in literature for priority setting in development process of clinical practice guidelines. Methods: We are conducting a systematic review to identify and summarize all methodological strategies and techniques used in priority setting for CPG development, implementation or evaluation. We searched for observational studies, descriptive studies, before and after studies, intervention studies, and guideline reports that describe a methodological approach to prioritization in practice guideline development. We are searching in MEDLINE (PubMed; January 1966 to February 2008), The Cochrane Library (Issue 1, 2008), LILACS (January 1982 to February 2008) and recognized government and nongovernment agencies in their publication databases. Basic search structure used is (‘‘Guideline‘‘[Publication Type] OR ‘‘Guidelines as Topic’’[Mesh] OR ‘‘Practice Guideline‘‘[Publication Type] OR clinical practice guideline*[tw] OR public health guideline*[tw]) AND (Health Priorities[mh] OR Health Priorities[tw] OR priority setting[tw] OR setting priorities[tw] OR (prioritization method*[tw]) OR (prioritizing method*[tw])), and it will be adapted for each database. Finally, we will contact experts in the area to find additional references. Methods reported and conclusions will be extracted by one reviewer. Data extraction will be organized in four questions: What are the published prioritization approaches (methodologies) for CPG development? What are the usual participants and selection approaches? What are the criteria used in CPG topic selection? What methods are used to weight the chosen criteria? Results: We expect a systematic summary of methods, participants, topic selection criteria and weighting systems in priority setting for CPG development, valuable information for policy makers, healthcare administrators, public health agencies, CPG developers and researchers. Conclusions: Methods in CPG priority setting.