Background: Professional societies, like many other organizations around the world, have recognized the need to use more rigorous processes to ensure that health care recommendations are informed by the best available research evidence. This is the third of a series of 14 articles that were prepared to advise guideline developers in respiratory and other diseases on considerations for group compositions and group processes in guideline development, and how this can be effectively integrated in the context of respiratory disease guidelines on a national and international level. Methods: We updated a review of the literature addressing group composition and group process, focusing onthe following questions: 1. How to compose a functioning and representative guideline group • Who should be included in a guideline panel? • How to select organizations, groups, and individuals • What expertise is needed? • Consultation with nonincluded groups 2. How to assure a functioning group process • How to make the process constructive • Balancing participation and finding agreement • Administrative support • What constitutes sufficient resources? Our conclusions are based on available evidence from published literature, experience from guideline developers, and workshop discussions. Results and Conclusions: Formal studies addressing optimal processes in developing guidelines are limited, and experience from guideline organizations supplement the formal studies. When resources are available, guideline development groups should aim for multidisciplinary groups, including patients. Prerequisites for a multidisciplinary group include: a strong chair experienced in group facilitation with broad acceptance in the group, training the group in guideline methodology, and professional technical support. Formal consensus developing methods have proved effective in reaching agreement on the final recommendations.