A new guideline-development checklist for researchers. A guideline-development checklist, published in the Canadian Medical Association Journal (online December 16, 2013), provides practical steps, tools, and resources to help create high-quality health care guidelines. Few tools are available for creating guidelines, despite the many tools that exist for evaluating them. The checklist comprises 18 topics and 146 items, with links to resources and training materials to track progress and prevent developers from missing crucial steps. Both new and expert designers can use the comprehensive checklist to plan, formulate, implement, evaluate, and update guidelines. The checklist will be tested and updated through feedback from crowdsourcing. It can be accessed at http://www.guidelinedevelopment.org.